Effect of Preoperative Leg Length Discrepancy on Functional Outcome and Patient Satisfaction After Total Hip Arthroplasty in Cases of Osteonecrosis of the Femoral Head

Loss of walking independence one year after primary total hip arthroplasty for osteonecrosis of the femoral head: incidence and risk prediction model

BACKGROUND

Assessment of postoperative ambulation in osteonecrosis of the femoral head (ONFH) patients treated with total hip arthroplasty (THA) is limited. This study aimed to define the incidence and risk factors for losing walking independence (LWI) at one-year postoperatively in patients with ONFH undergoing primary THA, and to establish and validate a predictive nomogram.

METHODS

This was a retrospective analysis of prospective collected data from patients admitted to a tertiary referral hospital with ONFH who underwent primary unilateral THA from October 2014 to March 2018. The Functional Independence Measure-Locomotion scale was used to quantify walking independence and was documented at a one-year continuous postoperative follow-up, which classified patients with a final score below 6 as LWI. Multivariate logistic regression identified independent risk factors for LWI, and a predictive nomogram was constructed based on the analysis results. The stability of the model was assessed using patients from April 2018 to April 2019 as an external validation set.

RESULTS

1152 patients were enrolled in the study, of which 810 were used in the training cohort and the other 342 for the validation cohort. The incidence of LWI was 5.93%. Multivariate analysis revealed that age 62 years or older (odd ratio (OR) = 2.37, 95% confidence interval (CI) 1.07-5.24), Charlson's comorbidity index 3 or higher (OR = 3.64, 95% CI 1.09-12.14), Association Research Circulation Osseous stage IV (OR = 2.16, 95% CI 1.03-4.54), reduced femoral offset (OR = 2.41, 95% CI 1.16-5.03), and a higher controlling nutritional status score (OR = 1.14, 95% CI 1.01-1.30) were independent risk factors of LWI. The nomogram had a concordance index of 0.773 and a Brier score of 0.049 in the training set, with corrected values of 0.747 and 0.051 after internal validation. The receiver-operating characteristic curve, calibration curve, Hosmer-Lemeshow test, and decision curve analysis all performed well in both the training and validation cohorts.

CONCLUSIONS

This study reported a 5.93% incidence of LWI and established a risk prediction model in patients undergoing THA for ONFH, supporting targeted screening and intervention to assist surgeons in assessing ambulation capacity and managing rehabilitation.

An Analysis of Radiographic Leg Length Discrepancy and Hip Offset in Patients at Risk of Developing Osteoarthritis

Background

Leg length and hip offset are important principles in total hip arthroplasty (THA). Patients may endorse leg length differences (LLD) postoperatively that may be anatomical or functional. The objective of this study was to determine the normal radiographic variation in leg length and hip offset in a preosteoarthritic population without a THA.

Methods

A retrospective study was completed using data from the Osteoarthritis Initiative, a prospective longitudinal study. Patients at risk of developing or with early osteoarthritis without inflammatory arthritis or prior THA were included. Measurements were made from full limb length anterior-posterior (AP) radiographs. Multiple linear regression models were employed to predict side-to-side differences in LLD, Δ femoral offset (FO), Δ abductor muscle length (AML), Δ abductor lever arm, and Δ AP pelvic offset.

Results

The mean radiographic LLD was 4.6 mm, with 12 mm within 1 standard deviation. No significant differences were detected between LLD and sex, age, body mass index, or height. The median radiographic differences in FO, AML, abductor lever arm, and AP pelvic offset were 3.2 mm, 4.8 mm, 3.6 mm, and 3.3 mm, respectively. Height was predictive of Δ FO, while both height and age were predictive of Δ AML.

Conclusions

Radiographic leg length variations in a population without symptomatic or radiographic osteoarthritis exist. FO and AML are dependent on patient characteristics. Preoperative radiographic LLD is not predicted by age, gender, body mass index, or height. It should be stressed that anatomic reconstruction is one of the many goals of arthroplasty and can stand in conflict with the priority and primary goals of stability and fixation, which should be prioritized.

Intraoperative method of femoral head central measurement to prevent leg length discrepancy following hemiarthroplasty

Purpose

This study aimed to introduce and investigate the safety and efficiency of the intraoperative central measurement method of the femoral head (IM-CMFH) to prevent leg length discrepancies (LLD) after hemiarthroplasty.

Methods

Overall, 79 patients aged 75 to 85 years with femoral neck fractures who underwent hemiarthroplasty were divided into two groups: the Control group (n = 46) and the IM-CMFH group (n = 33). The two groups were compared for postoperative LLD and the proportions of patients with greater than 10 mm, 6-10 mm, and within 5 mm, postoperative femoral offset (FO) difference and the proportions of patients within 5 mm, incremental greater than 5 mm and reduction greater than 5 mm. Next, the vertical distance from the center of the femoral head to the tip of the greater trochanter on the anatomical axis of the femur (VD-CFH-TGTAAF), leg length, and FO on the operative and non-operative sides within the IM-CMFH group. Finally, operative time, hemoglobin loss, Harris scores 3 months after surgery, and postoperative complications were analyzed.

Results

Compared with the control group, the postoperative LLD and FO differences were significantly lower in the IM-CMFH group (P = 0.031; P = 0.012), and the proportion of patients with postoperative LLD greater than 10 mm decreased significantly (P = 0.041), while the proportion of patients with FO difference of within 5 mm increased (P = 0.009). In addition, there was no significant difference in the operative time, hemoglobin loss, and Harris score at 3 months postoperatively and postoperative complications between the two groups (P > 0.05). There was no significant difference in FO, leg-length, and VD-CFH-TGTAAF between the operative and non-operative sides within the IM-CMFH group (P > 0.05).

Conclusion

Satisfactory results can be achieved by using the IM-CMFH to prevent LLD following hemiarthroplasty, and there is no increase in operative time, hemoglobin loss, or postoperative complications. This technique is efficient for hemiarthroplasties and is both simple and convenient.

A simple method for restoring the femoral head center in hip arthroplasty: a 3-dimensional analysis in the Chinese population

Background

Various authors have successfully demonstrated that the distance from the greater trochanter to the femoral head center (GTFHC) and the distance from the lesser trochanter to the femoral head center (LTFHC) can be used as parameters to determine the recovery of the femoral head center (FHC) during hip arthroplasty. It is necessary to undertake an anatomical study concerning the correlations between the greater trochanter (GT), the lesser trochanter (LT), and the FHC using data obtained from the 3D-CT reconstruction method.

Methods

The study comprised 293 patients (151 males and 142 females), with an average age of 65.06 years. The femoral head diameter(FHD), the linear distance from FHC to GT (GTFHC), and the linear distance from FHC to LT(LTFHC) were all measured and recorded data. The correlation between FHD with LTFHC and GTFHC was assessed using Pearson correlation coefficients, and the ratio of LTFHC and GTFHC to FHD was calculated from this ratio. All measured parameters were compared between the left and right sides and the sexes of the participants.

Results

The average ratios of GTFHC/FHD and LTFHC/FHD were 0.99 and 0.95, respectively .96% of the LTFHC had absolute lateral differences of < 4 mm . 92% of the GTFHC had absolute lateral differences of < 4 mm.

Conclusion

LTFHC and GTFHC are reliable reference parameters for preoperative planning and reconstruction of FHC of hip arthroplasty. The ratio displayed in this research may yield insight into a practical and straightforward method for orthopedic surgeons to perform hip arthroplasty in patients with femoral neck fractures. Ratios from studies based on the same race may be desirable for future work.

Leg length measures appear inaccurate in the early phase following total hip arthroplasty

The aims of this study were to (1) assess reliability of leg length discrepancy (LLD) measurements at different anatomical landmarks, (2) longitudinally investigate LLD in patients within the first year following total hip arthroplasty (THA) and to (3) correlate changes in LLD with functional outcome. Ninety-nine patients with short stem THA (53.3% males, mean age: 61.0 ± 8.1 years) were prospectively included. Upright pelvic anteroposterior (a.p.) radiographs taken at 6 timepoints (preoperatively, discharge, 6, 12, 24, 52 weeks postoperatively) were used to assess LLD at 5 anatomical landmarks (iliac crest, upper sacroiliac joint, lower sacroiliac joint, tear drop figure, greater trochanter). WOMAC and Harris Hip Score (HHS) were obtained preoperatively and at 6 and 52 weeks. LLD measures significantly increased in the initial phase following THA, from discharge to 6 weeks postoperatively and remained constant thereafter. Documentation of LLDs is dependent on measurement site: LLDs varied significantly between trochanter and iliac crest to tear drop figure (p < 0.001). Functional assessments did not correlate with the occurrence of LLDs [WOMAC (p = 0.252); HHS (p = 0.798)]. Radiographic assessment of LLD following THA may not be performed early postoperatively, as measurements appear to inaccurately reflect actual LLDs at this time, potentially due incomplete leg extension and/or inhibited weight-bearing.

Leg-Length Change After Unilateral Unicompartmental Knee Arthroplasty in Varus Knee and Its Clinical Implications

BACKGROUND

To explore the magnitude of leg-length change after the unilateral index unicompartmental knee arthroplasty (UKA) in varus knee and its influence on clinical outcomes.

METHODS

A total of 114 patients with bilateral knee osteoarthritis who underwent unilateral UKA from June 2015 to June 2017 were included and followed up for at least 2 years. The leg length and hip-knee angle were measured on full-length standing films before and after the surgery. Flexion contracture was evaluated using a goniometer with the patient in the standing position preoperatively and postoperatively. Hospital for Special Surgery scores, perceived leg-length discrepancy (pLLD), the occurrence, and the time interval of subsequent contralateral knee arthroplasty were recorded and analyzed.

RESULTS

The average leg length increased after UKA was 9.39 ± 11.24 mm (range -21.00 to 33.79 mm), and 90 (78.9%) patients showed an increase in the leg length. 35 patients had LLD (defined as ≥10 mm), and 25 presented pLLD preoperatively; 25 patients had LLD, and 45 were suspected with pLLD postoperatively. At the last follow-up, 26 patients underwent subsequent contralateral knee arthroplasty. Postoperative LLD and pLLD were not associated with Hospital for Special Surgery scores of UKA but associated with subsequent contralateral knee arthroplasty.

CONCLUSIONS

LLD and pLLD were common in patients both before and after UKA. Most patients showed leg lengthening after UKA. Postoperative LLD and pLLD were not associated with functional scores but associated with a subsequent contralateral knee arthroplasty.

Factors associated with unaffected foot deformity in unilateral cerebral palsy

The aim of this study was to assess the angular components of the affected foot associated with valgus deformity of the unaffected foot and to redefine the actual leg-length inequality in unilateral cerebral palsy. We retrospectively reviewed the medical records and radiologic images of 76 patients with unilateral cerebral palsy. Weight-bearing plain radiography of both feet of each subject was obtained. Angular measurements focused on the collapse of the longitudinal arch, hind foot valgus and forefoot abduction. Patients were divided into two groups: with and without valgus deformity of the unaffected side. Leg-length discrepancy and pelvic obliquity angle were measured Among 76 patients, 40 (52%) had valgus deformities of the unaffected side. Independent t-test revealed no significant differences in age, affected side, type of deformity on the affected side, or application of bilateral biomechanical foot orthosis between patients with or without valgus deformity of the unaffected side. Patients with valgus deformity had significantly increased voluntary ankle dorsiflexion greater than neutral on the affected side, leg-length discrepancy and lateral talocalcaneal angle (P < 0.05). Laterally measured foot angles of both feet were significantly correlated. The optimal cut-off points for predicting valgus deformity were leg-length discrepancy >10 mm or affected limb/unaffected limb-length index <0.98. Leg-length discrepancy and lateral talocalcaneal angle of the affected foot were significantly increased in patients with valgus deformity of the unaffected side. The optimal cut-off point for predicting valgus deformity of the unaffected foot would be useful in clinical practice.

[Total hip replacement in avascular femoral head necrosis]

BACKGROUND

Avascular necrosis of the femoral head is a progressive perfusion disorder of the hip joint. Progress in avascular necrosis causes structural damage to the affected joint, often requiring total hip replacement.

AIM

This article is intended to give the reader an overview of the current literature on total hip replacement of patients with an avascular necrosis of the femoral head.

RESULTS

Before 1990, patients with avascular necrosis of the femoral head had significantly higher revision rates after total hip replacement. Recent studies, however, showed no significant differences in clinical outcomes after total hip replacement in femoral head necrosis and primary osteoarthritis. Despite the young age of the patients, good long-term clinical results can be expected even in patients with an avascular necrosis of the femoral head after total hip replacement.

Measurement of Patient's Perception on Limb-Length Discrepancy Compared With Weight-Bearing Orthoroentgenography in Total Hip Arthroplasty: A Prospective Study

BACKGROUND

Aims of this study included providing a comparison of the measurement of limb-length discrepancy after primary total hip arthroplasty between patient's perception and weight-bearing orthoroentgenographic measurement. A comparison between patient's perception and pelvic radiographic measurement was examined as well.

METHODS

This prospective study comprised patients who had already undergone total hip arthroplasty and were receiving postoperative outpatient care between April 2017 and July 2017. Block test was used to assess patient's perception on limb-length discrepancy. Weight-bearing orthoroentgenography and pelvic radiography were used for radiographic measurement. These 3 measurements were compared to find the difference, correlation, and reliability.

RESULTS

Evaluations were carried out on 68 patients subsequent to primary total hip arthroplasty. The prevalence of limb-length discrepancy by orthoroentgenographic, patient's perception, and pelvic radiographic measurements was 60%, 57.35%, and 52.94%, respectively. Mean difference of limb-length discrepancy between the 3 measurements were not statistically significant. When compared with orthoroentgenography, sensitivity and specificity of patient's perception measurement were 60.98% and 48.15%, respectively. Likewise, sensitivity and specificity of pelvic radiographic measurement were 78.05% and 85.19%, respectively. Poor correlation and reliability were found between orthoroentgenographic and patient's perception measurement (concordance correlation coefficient = 0.21, intraclass correlation coefficient = 0.22). However, good correlation and reliability were found between orthoroentgenographic and pelvic radiographic measurement (concordance correlation coefficient = 0.85, intraclass correlation coefficient = 0.85).

CONCLUSION

Patient's perception on limb-length discrepancy had poor correlation and reliability, low sensitivity and specificity when compared with orthoroentgenographic measurement. A physician should additionally perform measurement by orthoroentgenography or pelvic radiography.

Patient-reported outcomes in patients who undergo total hip arthroplasty after periacetabular osteotomy

BACKGROUND

There has been constant discussion about whether the clinical outcome of THA after periacetabular osteotomy (PAO) is equivalent to that after primary total hip arthroplasty (THA). However, there have been few reports about patient-reported outcomes (PRO) for those who undergo THA after PAO. We compared the pre- and postoperative PRO of patients who underwent THA after PAO and those who underwent primary THA alone.

METHODS

We performed a case-control study. Twenty-seven patients (29 hips) underwent THA after PAO (osteotomy group); their mean age at surgery was 57.2 years, and they underwent postoperative follow-up for a mean period of 3.0 years. For the control group, after matching age, sex, and Crowe classification, we included 54 patients (58 joints) who underwent primary THA for hip dysplasia. Assessment performed preoperatively and at the last follow-up included the Harris hip score, the Short Form 36 (SF-36) for the Physical Component Summary (PCS), Mental Component Summary (MCS), and Role/Social Component Summary (RCS) domains, Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ) for pain, movement, and mental health, and the visual analog scale (VAS) score of hip pain and satisfaction.

RESULTS

The two groups demonstrated no significant difference in the preoperative Harris hip score, each domain of the SF-36, JHEQ, and the VAS score of hip pain and satisfaction. The osteotomy group demonstrated significantly poor Harris hip scores for gait and activity, and JHEQ for movement at the last follow-up. There was no significant difference in each domain of the SF-36 and the VAS score of hip pain and satisfaction at the last follow-up.

CONCLUSION

Previous PAO affects the quality of physical function in patients who undergo subsequent THA.

Total Hip Arthroplasty After Transtrochanteric Rotational Osteotomy for Osteonecrosis of the Femoral Head: A Mean 10-Year Follow-Up

BACKGROUND

The objective of the present study was to investigate clinical, quality of life, and radiographic outcomes of patients who underwent total hip arthroplasty (THA) after transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH).

METHODS

We performed a case-control study. The participants were 29 patients (34 hips) who underwent THA after TRO (TRO group). These patients had a mean age at surgery of 51.6 years (range, 30-72 years) and underwent postoperative follow-up for a mean period of 10.5 years (range, 3-19 years). For the control group (primary group), we included 58 patients (68 hips) who underwent primary THA for ONFH, matching for age and gender.

RESULTS

The Harris Hip Scores at the last follow-up were significantly poorer in the TRO group than in the primary group. Similarly, preoperative and postoperative hip range of motion was significantly poorer in the TRO group than in the primary group. Quality of life (Short Form-36, Oxford Hip Score, and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire) and complication rates were not significantly different between the groups. The survival rates at 10 years, with revision for any reason as the endpoint, were 81% in the TRO group and 91% in the primary group, showing no significant difference between the groups. The TRO group had a larger average postoperative leg length discrepancy and a higher rate of stem malalignment than the primary group.

CONCLUSION

The clinical outcomes of THA after TRO for ONFH were poorer than those of primary THA.

The Accuracy of Digital Templating for Primary Total Hip Arthroplasty: Is There a Difference Between Direct Anterior and Posterior Approaches?

BACKGROUND

The direct anterior approach (DAA) has gained recent popularity for total hip arthroplasty (THA), as it provides immediate feedback on cup position and limb length using fluoroscopy. The purpose of this study is to evaluate any differences in the accuracy of digital templating for preoperative planning of THA, performed with 2 different surgical approaches: DAA using a radiolucent table with intraoperative fluoroscopy and the posterior approach (PA).

METHODS

One hundred thirty-one consecutive patients (148 hips) underwent a THA by a single surgeon, using the same cup and stem designs. Seventy-five hips were performed using the DAA using a fracture table and fluoroscopy. Seventy-three hips were performed using the PA with the patient positioned in lateral decubitus using standard positioners without fluoroscopy. Preoperative radiographs were digitally templated by the same surgeon.

RESULTS

The PA patients had a higher mean body mass index and were more likely to have a preoperative diagnosis of avascular necrosis. The accuracy of templating for predicting the cup size to be within 2 mm was 91% for DAA vs 88% for PA (P = .61). For stem size, the accuracy was 85% (to within 1 size) for the DAA vs 77% for the PA (P = .71). Likewise, there was no significant difference in predicting the final stem's neck angle or femoral offset.

CONCLUSION

Digital templating was found to be a reliable and highly accurate method for predicting component sizes and offset for THA, regardless of using either the PA or the DAA with fluoroscopy.