Effects of Artificially Induced Leg Length Discrepancy on Treadmill-Based Walking and Running Symmetry in Healthy College Students: A Lab-Based Experimental Study

Leg length discrepancy (LLD) is a common postural deviation of musculoskeletal origin, which causes compensatory reactions and often leads to injury. The aim of the study was to investigate the effect of artificially induced LLD on gait symmetry by means of the spatiotemporal gait parameters and ground reaction forces (GRFs) using a treadmill equipped with capacitive sensors (instrumented) as well as the EMG activity of trunk and hip muscles during walking and running. Twenty-six healthy male and female college students were required to perform two sets of four 2.5-min walking and running trials on an instrumented treadmill at 5.6 and 8.1 km·h-1, respectively, without (0) and with 1, 2, and 3 cm LLD implemented by wearing a special rubber shoe. Statistical analysis was performed using one-way repeated measures or a mixed-design ANOVA. Most spatiotemporal gait parameters and GRFs demonstrated an increase or decrease as LLD increased either on the short-limb or the long-limb side, with changes becoming more apparent at ≥1 cm LLD during walking and ≥2 cm LLD during running. The EMG activity of trunk and hip muscles was not affected by LLD. Our findings showed that gait symmetry in terms of treadmill-based spatiotemporal parameters of gait and GRFs is affected by LLD, the magnitude of which depends on the speed of locomotion.

Combined Femoral Osteotomy and Contralateral Hip Arthroplasty to Correct Limb Alignment and Arthritis in a Scoliosis and Polio Patient: A Case Report

We describe the first case of a 62-year-old female symptomatic patient with multiple comorbidities presenting with coronal limb malalignment due to scoliosis and osteoarthritis who underwent a combined total hip arthroplasty and biplane opening wedge osteotomy of the distal femur in one procedure. It is essential to realize that in patients who present with multiple comorbidities, combining different established procedures should be considered as a therapeutic option. We detail the operative procedure, preoperative considerations, and postoperative rehabilitation. By reviewing the literature on operative techniques, we highlight how our findings can be applied to similar cases with multiple comorbidities. Our report underscores the importance of considering combined procedures as a viable therapeutic option for patients with complex medical histories.

Can a structural leg length discrepancy contribute to persistent concussion symptoms? A case report

In the past several years, concussions and post-concussion syndrome (PCS) have become more commonly recognized conditions. However, with limited physiological explanation for post-concussion syndrome, there is also limited evidence supporting effective treatment. The vestibular system plays a role in postural reflexes and coordinated eye and cervical spine movements and is often disrupted in patients with prolonged concussion symptoms. This disruption has contributed to some of the most debilitating symptoms in PCS patients including dizziness, nausea, and balance deficits. Ongoing, post-concussion, vestibulo-ocular/cervical-ocular disruption due to an underlying structural leg length discrepancy as a contributing factor has not been previously described in the literature. A case of PCS with initial conservative treatment of their structural leg length discrepancy and subsequent vestibulo-ocular/cervical-ocular rehabilitation is presented.

Utilizing Three-Dimensional Head-Lesser Trochanter Distance Could Further Reduce Leg Length Inequality in Primary Bipolar Hemiarthroplasty

Background: The aim of this study was to investigate whether the use of three-dimensional (3-D) computed tomography (CT)-based head-lesser trochanter distance (HLD) could reduce leg length discrepancy (LLD) more than the use of a two-dimensional (2-D) plain film method in primary bipolar hemiarthroplasty. Methods: Propensity score matching (PSM) analysis was used to adjust the confounding factors. A retrospective comparative analysis of 128 patients was performed. In the control group, the leg length was equalized using the 2-D, plain film-based HLD. In the study group, primary bipolar hemiarthroplasty was performed using the 3-D CT-based HLD method. Postoperative LLDs were compared between the two groups using the method of Ranawat. In addition, the Harris hip score (HHS) was evaluated and compared at one year after surgery. Results: A significant difference was observed in mean postoperative LLD between the 2-D HLD group and the 3-D CT HLD group: 1.6 ± 1.2 mm (range, 0.1−6.0 mm) and 1.1 ± 1.2 mm (range, 0.1−5.1 mm), respectively (p < 0.05). Additionally, a higher percentage of patients in the 3-D CT HLD group had an LLD of less than 2 mm. The mean HHS at one year after surgery showed no significant difference between the two groups. Conclusions: To minimize the occurrence of LLD, HLD measurement from a CT scanner may be more accurate than an X-ray. The 2-D and 3-D HLD differences in the 3-D CT HLD group were statistically significant. Using a 3-D, CT-based HLD method might decrease the possibility of an LLD over 2 mm.

Intra and intersession repeatability and reliability of dynamic parameters in pressure platform assessments on subjects with simulated leg length discrepancy. A cross-sectional research

BACKGROUND

Leg length discrepancy (LLD) may play a key role in exercise biomechanics. Although the Podoprint platform has been used in dynamic pressure studies, there are no data regarding the reliability and repeatability of dynamic measurements under simulated LLD conditions.

OBJECTIVES

To determine the intra and intersession repeatability and reliability of dynamic parameters of the Podoprint pressure platform under simulated LLD conditions.

DESIGN AND SETTING

Observational cross-sectional study at a public university.

METHODS

Thirty-seven healthy volunteers participated in this study. LLD was simulated using ethyl vinyl acetate plantar lifts with heights of 5 mm, 10 mm, 15 mm and 20 mm located under the right shoe of each volunteer. The procedure was performed to capture the dynamic parameters of each participant under five different simulated LLD conditions. Stance time, mean pressure and peak pressure measurements were registered in three trials for each foot and each LLD level. Data were collected during two separate testing sessions, in order to establish intrasession and intersession reliability.

RESULTS

The intraclass correlation coefficients (ICCs) for intrasession reliability ranged from 0.775 to 0.983 in the first session and from 0.860 to 0.985 in the second session. The ICCs for intersession reliability ranged from 0.909 to 0.990. Bland-Altman plots showed absence of systematic measurement errors.

CONCLUSIONS

The results from this study indicate that the Podoprint platform is a reliable system for assessing dynamic parameters under simulated LLD conditions. Future studies should evaluate plantar pressures under LLD conditions, in association with exercise, biomechanics and musculoskeletal disorders.

The Effect of Simulated Leg-Length Discrepancy on the Dynamic Parameters of the Feet during Gait-Cross-Sectional Research

Background: The effect of Leg-Length Discrepancy (LLD) on dynamic gait parameters has been extensively discussed. Podobarography is the study of foot-to-ground pressure distribution. It has been used to test plantar footprint deviations that could reveal pathology. Purpose: The aim of this study is to determine the effects of simulated LLD on dynamic gait parameters measured with a pressure platform in healthy subjects. Methods: Thirty-seven healthy subjects participated in observational cross-sectional research. A procedure was performed to capture the dynamic parameters of each participant under five different simulated LLD conditions. Support time, mean pressure, and peak pressure measures were registered on three trials for each foot and LLD level per session. An analysis of variance (ANOVA) test for repeated measures was performed to check for differences between the different simulated LLD levels. Results: The stance time of the short leg had no significant changes. The stance time of the long leg increased by 3.51% (p < 0.001), mean pressure of the short leg increased by 1.23% (p = 0.005), and decreased by 5.89% in the long leg (p < 0.001). Peak pressure of the short leg decreased by 2.58% (p = 0.031) and the long leg decreased by 12.11% (p < 0.001). Conclusions: This study demonstrates that increasing LLD causes an asymmetrical foot-loading pattern, with decreased mean and peak pressure on the longer limb, and consequently an overload on the short side. Furthermore, an increasing LLD causes increased stance time on the long leg.

Orthotic Insoles Improve Gait Symmetry and Reduce Immediate Pain in Subjects With Mild Leg Length Discrepancy

Background: Mild leg length discrepancy can lead to musculoskeletal disorders; however, the magnitude starting from which leg length discrepancy alters the biomechanics of gait or benefits from treatment interventions is not clear.

Research question: The aim of the current study was to examine the immediate effects of orthotic insoles on gait symmetry and pain on mild leg length discrepancy according to two groups of the leg length discrepancy (i.e., LLD ≤ 1 cm vs. LLD > 1 cm).

Methods: Forty-six adults with mild leg length discrepancy were retrospectively included and classified into two groups (G_LLD≤1cm or G_LLD>1cm). All subjects underwent routine 3D gait analysis with and without orthotic insoles. The symmetry index was calculated to assess changes in gait symmetry between the right and left limbs. Pain was rated without (in standing) and with the orthotic insoles (after 30 min of use) on a visual analog scale.

Results: There was a significant improvement in the symmetry index of the pelvis in the frontal plane (p = 0.001) and the ankle in the sagittal plane (p = 0.010) in the stance with the orthotic insoles independent from the group. Pain reduced significantly with the orthotic insoles independently from the group (p < 0.001).

Significance: Orthotic insoles significantly improved gait symmetry in the pelvis in the frontal plane and the ankle in the sagittal plane, as well as pain in all subjects (both LLD ≤ 1 cm and LLD > 1 cm) suggesting that it may be appropriate to treat even mild leg length discrepancy.

Hip surgeons and leg length inequality after primary hip replacement

BACKGROUND:

This study reports the results of 2 separate surveys of British Hip Society (BHS) members relating to leg length inequality (LLI) after primary total hip replacement (THR).

SURVEY 1:

Investigates the members' opinions on the effect of LLI on the outcome of THR and explores the acceptable limits of LLI.

SURVEY 2:

Reports on the intraoperative techniques currently used by BHS members to minimise LLI after THR.

RESULTS - SURVEY 1:

97% of all surgeons completing the survey believed that LLI can affect the outcome of THR.

RESULTS - SURVEY 2:

All surgeons reported using at least 1 intraoperative technique for assessing leg length with a median of 5 techniques. Over 50% of surgeons use 2 or more tests.

CONCLUSION - SURVEY 1:

89% of surgeons agreed that 15 mm of LLI after primary uncomplicated THR was always acceptable. 90% of surgeons felt that LLI more than 22.74 mm was never acceptable.

CONCLUSION - SURVEY 2:

Despite the multiple published papers on various methods of assessing leg length intraoperatively, the problem of LLI post THR persists. This study highlights the need for further research to develop a simple intraoperative technique with high accuracy and reproducibility.

Predictors and Functional Implications of Change in Leg Length After Total Knee Arthroplasty

BACKGROUND

Leg lengthening occurs in 83% of primary total knee arthroplasty (TKA). The effects of leg length discrepancy (LLD) on THA patients are well established. However, patient function and satisfaction associated with LLD after primary TKA has not been analyzed. This study aimed to quantify the magnitude of limb lengthening, identify radiographic and perceived LLD, and correlate these with predictive factors and functional outcomes in a series of TKA patients.

METHODS

Patients undergoing primary TKA who met inclusion criteria were prospectively enrolled in this study. Leg length measurements were measured on standardized preoperative and postoperative long leg radiographs. Patients completed preoperative and 6-month postoperative Knee Society Score and functional Knee Injury and Osteoarthritis Outcome Score, as well as a postoperative satisfaction and customized leg length-specific functional questionnaire.

RESULTS

Ninety-one patients undergoing TKA surgeries were included. Mean overall lengthening was 3.5 mm (range, -31.0 to 21.4 mm; SD, 8.4) with 77% of limbs lengthened; 89% of patients had no LLD (defined as ≥10 mm) after TKA. Postoperative radiographic LLD was associated with increased preoperative LLD (P < .001). Perceived postoperative LLD was associated with female gender (P = .02), decreased satisfaction (18% vs 84%; P < .001), and poorer functional score changes. Perceived LLD was not associated with radiographic LLD.

CONCLUSION

Radiographic lengthened LLD is uncommon after primary TKA (11%) and does not correlate with perceived LLD. Patients with perceived LLD have decreased satisfaction and functional score improvements after TKA surgery.

Intraoperative measurement of limb lengthening during total hip arthroplasty

BACKGROUND

Limb length discrepancy (LLD) after total hip arthroplasty (THA) is a common problem which cannot be completely resolved. Many techniques have been described in order to minimize postoperative LLD, but most of these techniques are difficult to apply. Ideal technique must be simple and accurate. The most simple technique using a suture tied on the skin has well-known limitations, but its accuracy has not been evaluated before.

MATERIALS AND METHODS

Sixty THAs in sixty patients (mean age 71 years, 1:1 male to female ratio) with hip osteoarthritis (37 cases in the right, and 23 cases in the left side) were studied in this prospective study. In all surgeries, the intraoperataive measurement of limb lengthening was performed using a suture tied on the skin of the lateral pelvis. The accuracy of this technique and correlation between intraoperative and postoperative radiological measurements of lengthening were evaluated.

RESULTS

The mean preoperative LLD was -7.5 mm while the mean postoperative LLD was 1.58 mm. The accuracy of this technique, defined as the mean difference between the intraoperative and postoperative measurements was 1.8 mm. A strong correlation between these two measurements was noticed (r = 0.86).

CONCLUSION

The accuracy and correlation index of this simple technique were similar to those of other techniques. The studied technique is quite accurate when attention is given to certain details, such as the amount of tension applied on the suture, the position of the tied point on the skin, and the position of the leg during measurements.

Use of a magnetic bone nail for lengthening of the femur and tibia

PURPOSE

To report our experience with the PRECICE nail for limb lengthening in 23 patients.

METHODS

Records of 15 female and 8 male patients aged 14 to 38 (mean, 23.6) years who underwent lengthening of the tibia (n=6) or femur (n=21) using the PRECICE nail were reviewed. The reasons for lengthening included trauma (n=7), hemihypertrophy (n=2), focal femoral deficiency (n=2), Ellis-van Creveld syndrome (n=1), hip septic arthritis sequelae (n=1), hereditary multiple exostosis (n=1), club foot sequela (n=1), congenital tibial pseudoarthrosis (n=1), fibrous dysplasia (n=1), idiopathic limb length discrepancy (n=7), and cosmetic (n=1).

RESULTS

The mean follow-up duration was 20.72 months. The mean lengthening was 48.20 mm, and the mean acute angular correction was 15.5º. The mean time to full weight-bearing was 5.15 months, and the mean consolidation index was 1.12 months/cm. The mean maturation index was 0.78 months/cm. One patient had nail breakage during the consolidation phase. The nail was replaced by an intramedullary nail until consolidation, after which another PRECICE nail was used to treat the residual shortening. Eight patients had over-lengthening and the nails were driven back to the desired length. No patient had infection.

CONCLUSION

The PRECICE nail is a viable option for lengthening of the femur and tibia.

Z-plasty for severe gluteal muscle contracture in children

PURPOSE

To review the records of 363 patients with severe gluteal muscle contracture to determine its mechanism, underlying pathology, and treatment outcome.

METHODS

Records of 136 males and 227 females aged 5 to 18 (mean, 12.2) years who underwent Z-plasty for bilateral (n=347) or unilateral (n=16) severe gluteal muscle contracture were reviewed. Severe gluteal muscle contracture was classified as typical (n=52) or special (n=311). The typical type is associated with symptoms of positive out-toe gait, Ober sign, back-extending test, cross-leg test, squatting with knee side-by-side test, and hip dysfunction. It is further subdivided into mild (n=0), moderate (n=40), or severe (n=12). The special type is associated with additional symptoms of pelvic tilt and leg length discrepancy (<2 cm in 181 hips, 2-4 cm in 82 hips, and >4 cm in 48 hips). 311 hips had pelvic tilt and 47 hips had lumbar compensatory scoliosis. Treatment outcome was assessed at 6 months. Hip functional score was assessed at the final follow-up.

RESULTS

The mean hospitalisation period was 11 days. After a mean follow-up of 1.5 years, the mean hip functional score improved from 8.03 to 11.69; improvement was higher in children (age 5-13 years) than in adolescents (age 14-18 years) [3.7 vs. 2.9, p<0.001]. At 6 months, outcome was excellent in 280 hips, good in 80, fair in 3 hips, and poor in 0. The 3 hips with fair outcome had persistent slight pelvic tilt and swaying gait. Two of them had preoperative leg length discrepancy >4 cm, and intra-operatively the contracture band severely affected the joint capsule. The third patient did not comply with postoperative exercises.

CONCLUSION

Surgical treatment for severe gluteal muscle contracture achieved good outcome.

Management of anterior cruciate ligament tears in skeletally immature athletes

The prevalence of anterior cruciate ligament (ACL) injuries in skeletally immature athletes has increased dramatically over the past decade. Many attribute this to increased training, single-sport specialization and year-round competitive play. ACL injuries most commonly occur in athletic activities that involve cutting, pivoting, jumping and landing. Non-operative treatment consisting of activity modification, physical therapy and specialized bracing may have a role; however, recent data suggest that this may not be optimal in young, active patients. Surgical treatment has become more favorable, specifically for athletes with aspirations of higher-level sports participation. To minimize growth plate disturbances and potential for limb malalignment, the patient's skeletal age, pubertal status and remaining growth potential must be taken into consideration. We provide a review on how to evaluate, manage and treat the skeletally immature athlete with an ACL injury.

Total hip arthroplasty using a short-stem prosthesis: restoration of hip anatomy

PURPOSE

To evaluate hip parameters such as vertical centre of rotation (VCR), horizontal centre of rotation (HCR), femoral offset, and leg length after total hip arthroplasty (THA) using the Nanos short-stem prosthesis.

METHODS

Medical records of 73 men and 74 women aged 25 to 92 (mean, 63) years who underwent THA using the Nanos short-stem prosthesis by a single surgeon were reviewed. Prior to the surgery, the optimal cup and stem size, head length, and level of the neck osteotomy were determined using radiographs. Intra-operatively, the leg length and femoral offset were checked, and the level of neck resection and head length were adjusted. VCR, HCR, femoral offset, and leg length of the operated and contralateral sides were compared. Functional outcomes were assessed using the Harris Hip Score (HHS).

RESULTS

Compared with the normal contralateral hips, the operated hips had a mean increase of 0.4 mm in VCR (p=0.032), a mean decrease of 1.4 mm in HCR (p=0.027), a mean increase of 0.6 mm in femoral offset (p=0.043), and a mean increase of 0.36 mm in leg length (p=0.035). For these respective parameters, the difference between the normal contralateral side and the operated side was within 5 mm in 89%, 80%, 71%, and 96% of patients. The HHS improved from a mean of 53 to 91 at one year (p<0.001).

CONCLUSION

THA using the Nanos short-stem prosthesis enabled restoration of hip anatomy (VCR, HCR, femoral offset, and leg length).

Femoral pinless length and offset measurements during computer-assisted, minimally invasive total hip arthroplasty

We asked whether the intraoperative assessment of leg length (LL) and offset (OS) change would be accurate using a novel pinless femoral reference system during unilateral minimally invasive THA in 50 patients with a mean age of 60 years (48-79). LL and OS change measured at surgery was compared with LL/OS change as measured on magnification-corrected preoperative and postoperative radiographs by two blinded examiners. The radiographic evaluation showed a high inter-rater reliability (r > 0.80 for all assessments). The mean differences (± 95% limits of agreement) between navigation and radiographic measurements on the treated side were +0.4mm (± 3.6) for LL and -1.0 mm (± 3.9) for OS. Femoral pinless navigation technology represents a feasible assistance in THA.

The impact of leg length discrepancy on clinical outcome of total hip arthroplasty: comparison of four measurement methods

In a single-surgeon series of 119 patients with unilateral primary uncemented total hip arthroplasty, four leg-length discrepancy measurement methods (absolute, relative, trochanteric, standardized-trochanteric) were analyzed for their impact on WOMAC score, Oxford Hip Score and self-perceived leg-length discrepancy. After adjustment for age, gender and BMI, postoperative WOMAC scores correlated only with clinical absolute measurements of leg elongation (P=0.05). Self-perceived leg-length discrepancy corresponded best to the clinically measured relative leg-length discrepancy (11 mm perceived vs. 7 mm unperceived; P=0.04) while there was no significant correspondence with radiographic measurements or leg elongation magnitudes. Within the <10 mm range of mean postoperative leg length discrepancy in the studied series, its impact on the overall clinical satisfaction was detectable but not considerable.

The impact of leg length discrepancy on patient satisfaction and functional outcome following total hip arthroplasty

A series of 191 patients undergoing THA with a standardised stem were studied. The effect of leg length discrepancy (LLD) on patient function (Oxford Hip Score), health measures (Short Form 12) and satisfaction (Self-Administered Patient Satisfaction Scale) at a mean 3.8 years of follow up (range 3.3 to 4.9) is reported. 8.9% of cases had shortening, 0.5% no LLD and 90.6% had lengthening. In 21.5% the LLD was more than 10mm, in 37.1% 5-10mm, and in 40.9% 0-5mm. There was no significant difference in patient reported outcome measures (PROMs) according to LLD. Correlation of recorded measurements between multiple observers was excellent (0.93). LLD following total hip arthroplasty remains common but in this series, was not correlated with PROMs.

Association of leg-length inequality with knee osteoarthritis: a cohort study

BACKGROUND

Leg-length inequality is common in the general population and may accelerate development of knee osteoarthritis.

OBJECTIVE

To determine whether leg-length inequality is associated with prevalent, incident, and progressive knee osteoarthritis.

DESIGN

Prospective observational cohort study.

SETTING

Population samples from Birmingham, Alabama, and Iowa City, Iowa.

PATIENTS

3026 participants aged 50 to 79 years with or at high risk for knee osteoarthritis.

MEASUREMENTS

The exposure was leg-length inequality, measured by full-limb radiography. The outcomes were prevalent, incident, and progressive knee osteoarthritis. Radiographic osteoarthritis was defined as Kellgren and Lawrence grade 2 or greater, and symptomatic osteoarthritis was defined as radiographic disease in a consistently painful knee.

RESULTS

Compared with leg-length inequality less than 1 cm, leg-length inequality of 1 cm or more was associated with prevalent radiographic (53% vs. 36%; odds ratio [OR], 1.9 [95% CI, 1.5 to 2.4]) and symptomatic (30% vs. 17%; OR, 2.0 [CI, 1.6 to 2.6]) osteoarthritis in the shorter leg, incident symptomatic osteoarthritis in the shorter leg (15% vs. 9%; OR, 1.7 [CI, 1.2 to 2.4]) and the longer leg (13% vs. 9%; OR, 1.5 [CI, 1.0 to 2.1]), and increased odds of progressive osteoarthritis in the shorter leg (29% vs. 24%; OR, 1.3 [CI, 1.0 to 1.7]).

LIMITATIONS

Duration of follow-up may not be long enough to adequately identify cases of incidence and progression. Measurements of leg length, including radiography, are subject to measurement error, which could result in misclassification.

CONCLUSION

Radiographic leg-length inequality was associated with prevalent, incident symptomatic, and progressive knee osteoarthritis. Leg-length inequality is a potentially modifiable risk factor for knee osteoarthritis.

PRIMARY FUNDING SOURCE

National Institute on Aging.

Association of leg-length inequality with knee osteoarthritis: a cohort study

BACKGROUND

Leg-length inequality is common in the general population and may accelerate development of knee osteoarthritis.

OBJECTIVE

To determine whether leg-length inequality is associated with prevalent, incident, and progressive knee osteoarthritis.

DESIGN

Prospective observational cohort study.

SETTING

Population samples from Birmingham, Alabama, and Iowa City, Iowa.

PATIENTS

3026 participants aged 50 to 79 years with or at high risk for knee osteoarthritis.

MEASUREMENTS

The exposure was leg-length inequality, measured by full-limb radiography. The outcomes were prevalent, incident, and progressive knee osteoarthritis. Radiographic osteoarthritis was defined as Kellgren and Lawrence grade 2 or greater, and symptomatic osteoarthritis was defined as radiographic disease in a consistently painful knee.

RESULTS

Compared with leg-length inequality less than 1 cm, leg-length inequality of 1 cm or more was associated with prevalent radiographic (53% vs. 36%; odds ratio [OR], 1.9 [95% CI, 1.5 to 2.4]) and symptomatic (30% vs. 17%; OR, 2.0 [CI, 1.6 to 2.6]) osteoarthritis in the shorter leg, incident symptomatic osteoarthritis in the shorter leg (15% vs. 9%; OR, 1.7 [CI, 1.2 to 2.4]) and the longer leg (13% vs. 9%; OR, 1.5 [CI, 1.0 to 2.1]), and increased odds of progressive osteoarthritis in the shorter leg (29% vs. 24%; OR, 1.3 [CI, 1.0 to 1.7]).

LIMITATIONS

Duration of follow-up may not be long enough to adequately identify cases of incidence and progression. Measurements of leg length, including radiography, are subject to measurement error, which could result in misclassification.

CONCLUSION

Radiographic leg-length inequality was associated with prevalent, incident symptomatic, and progressive knee osteoarthritis. Leg-length inequality is a potentially modifiable risk factor for knee osteoarthritis.

PRIMARY FUNDING SOURCE

National Institute on Aging.

Symptoms of the knee and hip in individuals with and without limb length inequality

OBJECTIVE

This cross-sectional study examined the association of limb length inequality (LLI) with chronic joint symptoms at the hip and knee in a large, community-based sample, adjusting for the presence of radiographic osteoarthritis (OA) and other confounders.

METHODS

The total study group comprised 3012 participants with complete knee symptoms data, 3007 participants with complete hip symptoms data, and 206 with LLI>or=2 cm. Presence of chronic knee symptoms was defined as report of pain, aching, or stiffness (symptoms) of the knee on most days. Presence of chronic hip symptoms was defined as hip pain, aching, or stiffness on most days or groin pain. Multiple logistic regression models were used to examine the relationship of LLI with knee and hip symptoms, while adjusting for demographic and clinical factors, radiographic knee or hip OA and history of knee or hip problems (joint injury, fracture, surgery, or congenital anomalies).

RESULTS

Participants with LLI were more likely than those without LLI to have knee symptoms (56.8% vs 43.0%, P<0.001), and hip symptoms (49.5% vs 40.0%, P=0.09). In adjusted models, knee symptoms were significantly associated with presence of LLI (adjusted odds ratio [aOR]=1.41, 95% confidence interval, [95% CI] 1.02-1.97), but the relationship between hip symptoms and LLI (aOR=1.20, 95% CI 0.87-1.67) was not statistically significant.

CONCLUSION

LLI was moderately associated with chronic knee symptoms and less strongly associated with hip symptoms. LLI may be a new modifiable risk factor for therapy of people with knee or hip symptoms.

Relationship of limb length inequality with radiographic knee and hip osteoarthritis

OBJECTIVE

This study examined the relationship of limb length inequality (LLI) with radiographic hip and knee osteoarthritis (OA) in a large, community-based sample.

METHODS

The total study group comprised 926 participants with radiographic knee OA, 796 with radiographic hip OA, and 210 (6.6%) with LLI >or=2cm. The presence of radiographic OA was defined as Kellgren/Lawrence (K/L) grade >or=2. Multiple logistic regression models were used to examine the relationship of LLI with hip and knee OA, while controlling for age, gender, race, body mass index, and history of hip or knee problems (joint injury, fracture, surgery, or congenital anomalies).

RESULTS

In unadjusted analyses, participants with LLI were more likely than those without LLI to have radiographic knee OA (45.1% vs 28.3%, P<0.001) and radiographic hip OA (35.2% vs 28.7%, P=0.063). In multiple logistic regression models, knee OA was significantly associated with presence of LLI (adjusted Odds Ratio [aOR]=1.80, 95% Confidence Interval [95% CI] 1.29-2.52), but there was no significant relationship between hip OA and LLI (aOR=1.20, 95% CI 0.86-1.67). Among participants with LLI, right hip OA was more common when the contralateral limb was longer than when the ipsilateral limb was longer (30.3% vs 17.5%, P=0.070).

CONCLUSION

LLI was associated with radiographic knee OA, controlling for other important variables. Future research should examine the relationship of LLI with hip or knee OA incidence, progression, and symptom severity, as well as the efficacy for LLI corrective treatments in OA.

LEG LENGTH INEQUALITY AND THE SIDE OF LOW BACK PAIN

Objective: The objective of this paper is to investigate if there is a relationship between the side of leg length inequality (LLI) and the side of low back pain (LBP).

Design: Carefully standardised radiographic technique as described by Giles (1,2) and reviewed by Rock (3) was utilised to evaluate LLI in individuals who presented for assessment of LBP. Age, sex and the side of LBP were extracted from patient records. The side of LBP was determined by marking a pain diagram, taking the form of a body outline, included in the patient questionnaires. These findings were examined to reveal any relationship between the side of LLI and the side of LBP.

Setting: The study was conducted in a private chiropractic practice.

Participants: From January 1993 to September 1993 all patients presenting for chiropractic assessment of LBP where included. Patients whose history revealed relevant trauma, surgery or whose radiographic examination showed anomaly or pathology, likely to confound results, were excluded from the study.

Results and Conclusion: A relationship has been demonstrated between the LLI side and the side of LBP. The broad age range of subjects may well have been a confounding factor in this study. Re-analysis of the sample of patients aged 34 years or less demonstrated that the LBP side is most commonly opposite the side of LLI.