Lumbar Spine Fusion and Symptoms of Leg Length Discrepancy After Hip Arthroplasty

BackgroundHip length discrepancy (HLD) is common after total hip arthroplasty (THA); however, the effect of spinal fusion on perceived leg length discrepancy (LLD) symptoms after THA has not been examined. This study tested the hypothesis that LLD symptoms are increased in patients who underwent lumbar spinal fusion and THA, compared with patients with THA only.MethodsThis retrospective cohort study included 67 patients who underwent lumbar spinal fusion and THA, along with 78 matched control patients who underwent THA only. Hip and spine measurements were taken on postoperative, standing anterior-posterior pelvic, lateral lumbar, and anterior-posterior lumbar spinal radiographs. Perceived LLD symptoms were assessed via telephone survey.ResultsBetween the spinal fusion and control groups, there was no significant difference in HLD (M = 7.10 mm, SE = 0.70 and M = 5.60 mm, SE = 0.49) (P = .403). The spinal fusion patients reported more frequently noticing a difference in the length of their legs than the control group (P = .046) and reported limping “all the time” compared with the control group (P = .001). Among all patients with an HLD ≤10 mm, those in the spinal fusion group reported limping at a higher frequency than patients in the control group (P = .008). Patients in the spinal fusion group were also more likely to report worsened back pain after THA (P = .011) than the control group.ConclusionFrequencies of a perceived LLD, limping, and worsened back pain after THA were increased in patients with THA and a spinal fusion compared with patients who had THA only, even in a population with HLD traditionally considered to be subclinical. The results indicate that in patients with prior spinal fusion, precautions should be taken to avoid even minor LLD in the setting of THA.     

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 10 mm, in 37.1% 5–10 mm, and in 40.9% 0–5 mm. 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.     

Chinese Patients' Satisfaction With Total Hip Arthroplasty: What Is Important and Dissatisfactory?

Through validated self-administered questionnaires, we conducted a retrospective investigation in 818 patients (1009 hips) who underwent primary THA, to collect data on overall satisfaction plus satisfaction and importance rating for 16 specific functions and issues. Overall, 8.1% patients were dissatisfied with the surgery. The top 3 important items are pain relief, squatting, and walking. The top 3 dissatisfactory items are jogging, squatting, and rising after squatting. The strongest risk factors for dissatisfaction with walking were pain (6.1 ×), muscle weakness(3.7 ×), and LLD (3.3 ×). The strongest risk factors for dissatisfaction with squatting were low postoperative HHS ROM (3.7 ×) and muscle weakness (2.6 ×). For Chinese patients, ROM, muscle strength and LLD are very important.     

A simple and accurate method for determining leg length in primary total hip arthroplasty

Reconstruction of appropriate leg length is an important part of soft-tissue balance in total hip arthroplasty (THA). Leg length discrepancy (LLD) is one of the more common reasons for litigation after otherwise successful THA. The purpose of the study reported here was to analyze the accuracy of using preoperative templating and intraoperative referencing of the well leg to determine postoperative leg length in unilateral primary THA. Seven-hundred primary THAs performed at an institution by 3 surgeons were randomly selected from a computerized database. Cases with significant bilateral disease, congenital dysplasia, acute fracture, or previous surgery or without complete preoperative and postoperative radiographs were excluded. Three reviewers used a standardized method to measure preoperative and postoperative LLD. Included in the review were 410 THAs. Mean postoperative LLD was 3.9 mm lengthening (SD, 7.5 mm). In 20 THAs (4.9%), lengthening was more than 15 mm. Lengthening was more than 20 mm (maximum, 22 mm) in 4 THAs (1%). Of the 20 THAs with LLD of more than 15 mm, 14 involved hips that were longer preoperatively. Thirteen of these hips were reconstructed to within 10 mm of preoperative LLD. Only 2 patients with radiographic LLD of more than 15 mm perceived LLD. There were no differences in gender, height, weight, or body mass index. This method of preoperative templating and referencing the well leg intraoperatively is an inexpensive, reliable, and accurate method for determining leg length in primary THA and has few significant radiographic or clinical outliers.     

Wear Comparison Between Conventional and Highly Cross-Linked Polyethylene Against a Zirconia Head : A Concise Follow-Up,at an Average 10 Years,of a Previous Report

We previously reported the results of wear comparison at a minimum of 5 years between highly cross-linked polyethylene (HXLPE) and conventional polyethylene (PE) against a zirconia femoral head. We now report the mean wear at 10 years for 52 patients (56 hips) of the original cohort of 61 patients (65 hips) who had undergone primary total hip arthroplasty at our hospital between November 1999 and August 2000. The mean steady-state linear wear rate of HXLPE was 0.045 mm/y, compared with 0.080 mm/y for conventional PE (P = .0003). The incidence of osteolysis was 25% in the conventional PE group compared with 0% in the HXLPE group. Our study demonstrated that the steady-state wear rate for HXLPE remains significantly lower than that for conventional PE against a zirconia femoral head at a mean of 10 years after implantation.     

A Modified S-ROM Stem in Primary Total Hip Arthroplasty for Developmental Dysplasia of the Hip

This study examined the clinical outcome of 220 hips in 196 Asian patients who underwent primary total hip arthroplasty (THA) for treatment of developmental dysplasia of the hip (DDH) using a modified S-ROM modular (S-ROM-A) stem designed for Asians, after 2–5 years (mean, 3.3 years) of follow-up. The stem was placed so that the anteversion angle of the neck was decreased against the sleeve in 56% of the hips and increased in 18% of the hips. Bone ingrown fixation was achieved in 99.5% of the hips on X-ray at final follow-up. There were 2 (0.9%) dislocations postoperatively. In primary THA for treatment of DDH accompanied by femoral rotational deformity, the freely-rotatable modular stem provided favorable short-term outcomes by affording both morphological and functional advantages.     

Preoperative Leg Length Discrepancy >2 cm in the Supine Decubitus Position May Induce Compensatory Pelvic Obliquity in Patients during Total Hip Arthroplasty

Objectives

The leg length discrepancy (LLD) in the supine decubitus position may influence the inclination angle of the acetabular component during total hip arthroplasty (THA). The relationship among LLD, pelvic obliquity, and inclination angle of the acetabular component has not been well studied. This study aimed to evaluate the relationship between LLD in supine position and changes in the inclination angle of the acetabular components during THA, and the compensatory ability of the pelvis based on LLD and inclination.

Methods

A total of 135 patients were prospectively classified into three groups according to the preoperative LLD in the supine decubitus position: the cranial type group had a positive LLD value; the fixed type group had LLD = 0; and the caudal type group had a negative LLD value. Patients in the cranial type group and caudal type group were divided into four subgroups based on the LLD value (either positive or negative): LLD >3 cm subgroup; 2 ≤ LLD ≤ 3 cm subgroup; 1 ≤ LLD < 2 cm subgroup; and LLD <1 cm subgroup. The targeted and final inclination of the acetabular component was measured intra- and postoperatively.

Results

The results showed a significant difference in the targeted and final inclination angles among the patients in the cranial type and the caudal type groups. In the caudal type group, increased inclination was observed in the patients of LLD >3 cm subgroup (mean 3.13°) and 2 ≤ LLD ≤ 3 cm subgroup (mean 5.17°) after THA, respectively. Decreased inclination (mean, 6.16°) was observed in 2 ≤ LLD ≤ 3 cm subgroup in the cranial type group after THA.

Conclusions

Our findings revealed that in patients with discrepancy greater than 2 cm, postural pelvic obliquity imposed a remarkable influence on the inclination.     

A Report on Three Consecutive Cases using Computer Tomography 3D Preoperative Planning for Conversion of Arthrodesed Hips to Total Hip Replacements

Background

Conversion of an arthrodesed hip to a total hip arthroplasty (THA) is a technically demanding procedure with high complication rates. One important issue is that determining the amount of correction for a leg length discrepancy (LLD) can be difficult at the planning stage.

Questions/Purposes

The aim of this study is to assess the reliable use of computer tomography (CT)-based three-dimensional (3D) preoperative planning for the conversion of arthrodesed hips to THAs.

Patients and Methods

CT-based preoperative 3D planning was used to convert three arthrodesed hips to THAs. The efficacy of the planning was evaluated with postoperative radiographic measurements involving the amount of correction for LLD, position of components, difference between targeted and actual values, and ratio of the moment arms. The clinical assessment was performed with the Japanese Orthopaedic Association (JOA) hip score before and after THA.

Results

The mean amount of LLD correction and median LLD after THA were 16 mm (range, 15–17 mm) and 4 mm (range, 1–10 mm), respectively. The components were implanted close to the positions recommended by the preoperative simulation. The ratio of the moment arms indicated that the converted hips were reconstructed in a biomechanically correct manner. The implants for the conversion to THA were successfully positioned with respect to anatomy and functional outcome. The median JOA hip score improved from 50 points (range, 30–66 points) preoperatively to 79 points (range, 72–86 points) at the latest follow-up.

Conclusions

CT-based preoperative 3D planning could be a powerful guidance tool for conversion of arthrodesed hips to THAs.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9423-7) contains supplementary material, which is available to authorized users.     

Changes in Bone Mineral Density of the Acetabulum and Proximal Femur After Total Hip Resurfacing Arthroplasty

Our aim was to investigate the changes in bone mineral density (BMD) of acetabulum and proximal femur after total hip resurfacing arthroplasty. A comparative study was carried out on 51 hips in 48 patients. Group A consisted of 25 patients (26 hips) who had undergone total hip resurfacing and group B consisted of 23 patients (25 hips) who had had large-diameter metal-on-metal total hip arthroplasty (THA). BMDs around the acetabulum and proximal femur were measured using dual-energy x-ray absorptiometry (DEXA) at 2 weeks, 6 months, 1 year and annually thereafter during the 3 years after surgery. At final follow-up, the acetabular net mean BMD decreased by 11% in group A and 10% in group B with no differences between two groups (P = .35). For the femoral side, in Gruen zone 1, the mean BMD increased by 4% in group A, whereas it decreased by 11% in group B (P = .029). In Gruen zone 7, the mean BMD increased by 8% at the final follow-up in group A, whereas it decreased by 13% in group B (P = .02). In both groups the mean BMD increased by 3% in Gruen zones 3, 4, 5, and 6. Stress-related bone loss of the acetabulum was comparable for MOM THA and resurfacing devices, but proximal femoral bone density increased in the resurfacing group and decreased in the THA group.     

Gait Analysis of Leg Length Discrepancy—Differentiated Hip Replacement Patients With Developmental Dysplasia: A Midterm Follow-Up

Background

Few studies investigate gait characteristics and symmetry of developmental dysplasia of the hip patients (Crowe II and III) after total hip arthroplasty (THA) whose leg length discrepancy (LLD) is within 20 mm. Our study aimed to explore whether gait analysis parameters in these patients can return to the level of unaffected people and how bodies compensate for the discrepancy.

Cementless Total Hip Arthroplasty in Patients with Osteonecrosis After Kidney Transplantation

This study was to determine the mid- to long-term survivorship of cementless metal-on-metal THA in 52 patients (74 hips) who underwent THA for osteonecrosis of the femoral head with a cementless THA. The mean follow-up was 10.2 years. The mean age at operation was 42.1 years (range, 25–62 years). The survivorship analysis with revision as the end point estimated a 96.6% chance of THA survival during 16.4 years. The average Harris hip score at last follow-up was 89.2 points (range, 74–100). Two patients (two hips) required revision surgery for extensive acetabular osteolysis at 9 years and acetabular liner dissociation at 2 years. The survival rates of cementless THA in these patients are encouraging. However, the possibility of metallic wear related complications are raising concern.     

Additive Influence of Hip Offset and Leg Length Reconstruction on Postoperative Improvement in Clinical Outcome After Total Hip Arthroplasty

Background

There is a lack of prospective studies investigating the additive effect of both acetabular and femoral reconstruction parameters on the functional outcome following total hip arthroplasty (THA).

Limb Length Discrepancy in Total Hip Arthroplasty: Is the Lesser Trochanter a Reliable Measure of Leg Length?

BackgroundLimb length discrepancy (LLD) after total hip arthroplasty may affect clinical outcomes and patient satisfaction. Preoperative LLD estimates on anteroposterior pelvic radiographs fail to account for anatomical limb variation distal to the femoral reference points. The objective of this study is to determine how variations in lower limb skeletal lengths contribute to true LLD.MethodsFull-length standing anteroposterior radiographs were used to measure bilateral leg length, femoral length, and tibial length. Leg length was evaluated using 2 different proximal reference points: the center of the femoral head (COH) and the lesser trochanter (LT). Mean side-to-side discrepancy (MD) and percentage asymmetry (%AS) for each measurement were evaluated in the overall cohort and when stratified by patient demographic variables.ResultsOne hundred patients were included with an average age of 62.9 ± 11.2 years. Average femoral length was 434.0 ± 39.8 mm (MD 4.3 ± 3.5 mm) and tibial length was 379.9 ± 34.6 mm (MD 5.9 ± 12.7 mm). Average COH-talus was 817.5 ± 73.2 mm (MD 6.4 ± 5.1 mm). Average LT-talus was 760.5 ± 77.6 mm (MD 5.8 ± 5.1 mm). Absolute asymmetry >10 mm was detected in 16% of patients for COH-talus and 15% for LT-talus, while %AS >1.5% was detected in 13% of patients for COH-talus and 18% for LT-talus. Female gender was associated with increased femoral length %AS (P = .037).ConclusionApproximately 1 in 6 patients have an LLD of >10 mm when measured from either the LT or COH. Surgeons using either of these common femoral reference points to estimate LLD on pelvic radiographs should consider these findings when planning for hip reconstruction.Level of EvidenceLevel III.     

Accurate Leg Length Measurement in Total Hip Arthroplasty: A Comparison of Computer Navigation and a Simple Manual Measurement Device

Background

Several studies have shown that better placement of the acetabular cup and femoral stem can be achieved in total hip arthroplasty (THA) by using the computer navigation system rather than the free-hand alignment methods. However, there have been no comparisons of the relevant clinical advantages in using the computer navigation as opposed to the manual intraoperative measurement devices. The purpose of this study is to determine whether the use of computer navigation can improve postoperative leg length discrepancy (LLD) compared to the use of the measurement device.

Methods

We performed a retrospective study comparing 30 computer-assisted THAs with 40 THAs performed using a simple manual measurement device.

Results

The postoperative LLD was 3.0 mm (range, 0 to 8 mm) in the computer-assisted group and 2.9 mm (range, 0 to 10 mm) in the device group. Statistically significant difference was not seen between the two groups.

Conclusions

The results showed good equalization of the leg lengths using both computed tomography-based navigation and the simple manual measurement device.     

Changes in Early Serum Metal Ion Levels and Impact on Liver,Kidney, and Immune Markers Following Metal-on-Metal Total Hip Arthroplasty

We retrospectively studied 32 consecutive patients (32 hips) who underwent THA with a Durom large-head, MOM articulation between January 2008 and December 2010. Of the patients who underwent THA using a Trilogy metal on polyethylene prosthesis during the same period, 32 were chosen to form the Trilogy group. 32 volunteers were chosen to form the control group. At the last follow-up, serum metal ion levels, liver and kidney function and host immunologic immune responses were evaluated. The mean Co and Cr levels in the Durom group were 4.33- and 1.95-fold higher than those in the Trilogy group. CD3 +, CD4 + and CD8 + cell levels in the Durom group were significantly decreased. The INF-γ level in the Durom group was significantly higher than that in the Trilogy and control groups.     

The Development of Leg Length Difference and Influence on Persistent Dysplasia in Patients with Developmental Dysplasia of the Hip

IntroductionLeg-length difference (LLD) is common in patients with developmental dysplasia of the hip (DDH). LLD of > 1 cm at skeletal maturity is reported in > 40% of patients, with the majority related to ipsilateral overgrowth. A longer DDH leg might lead to excessive mechanical loading at the acetabular margin, resulting in compromised acetabular development. We hypothesised that the LLD would negatively influence acetabular development. If so, it would be advantageous to identify such patients early in the course of follow-up, and address this if necessary.MethodsA retrospective study was conducted on a consecutive series of DDH patients managed surgically at the Royal National Orthopaedic Hospital, Stanmore, United Kingdom. We included patients with adequate long-leg radiographs at the age of 4–8 years (early-FU) and skeletal maturity (final-FU). Bilateral cases and those who underwent surgical procedures for hip dysplasia during the follow-up period were excluded. Measurements including leg length and centre-edge-angle (CE-angle) were obtained at the 2 time points.ResultsTwenty-seven patients were included, mean age at early-FU 5.7 (± 0.9) years, and 13.9 (± 1.0) years at final-FU. Mean LLD at early-FU was 9.5 (± 7.6) mm and 10.9 (± 9.4) mm at final-FU, p = 0.337. Correlation between early- and final-FU LLD was 0.68 (p < 0.001). The mean CE-angle at early follow-up was 14.6° (± 9.8), this improved to 23.2° (± 8.2) at skeletal maturity (p = 0.003, paired samples t-test). Linear regression analysis showed a non-significant trend towards less CE-angle improvement in patients with more initial residual dysplasia and more initial LLD.ConclusionMost leg-length differences can be identified early in the follow-up period, nevertheless, considerable individual changes in LLD are observed on continued follow-up. Furthermore, a trend was observed towards impaired acetabular improvement in patients with more LLD. These findings justify careful clinical and radiological monitoring of LLD from an early stage in the follow-up period.Supplementary InformationThe online version contains supplementary material available at 10.1007/s43465-021-00492-5.     

Plain Radiographs Fail to Reflect Femoral Offset in Total Hip Arthroplasty

Successful biomechanical reconstruction is a major goal in total hip arthroplasty (THA). We measured leg length (LL), global (GO) and femoral offset (FO) change on anteroposterior pelvis radiographs and on three-dimensional computed-tomography (3D-CT) with fiducial landmarks after cementless THA on 18 hips of cadaveric specimens. Measurements on radiographs were performed twice by four examiners and showed high interobserver (mean CCC ≥ 0.79) and intraobserver agreements (mean ICC ≥ 0.88). Mean differences between radiographic and 3D-CT measurements were 1.0 (SD 2.0) mm for LL, 0.6 (SD 3.6) mm for GO and 1.4 (SD 5.2) mm for FO. 1% of radiographic LL-, 15% of GO- and 35% of FO measurements were outside a tolerance limit of 5 mm. Radiographs seem acceptable for measuring LL/GO change but fail to reflect FO change in THA.     

Leg Length Change After Curved Periacetabular Osteotomy and Its Impact on the Clinical Outcomes

BackgroundCurved periacetabular osteotomy (CPO) is one of the periacetabular osteotomies for the treatment of acetabular dysplasia. Several complications have been described after CPO, however, there have been no reports on the leg length change (LLC). This study aimed to investigate the LLC after CPO and its impact on the clinical outcomes.MethodsThis study was a retrospective review of 70 consecutive hips in 67 patients with symptomatic acetabular dysplasia who underwent CPO between March 2016 and April 2019. Preoperative and postoperative leg lengths were measured using anteroposterior radiographs, and the clinical outcomes were evaluated based on the Harris hip score (HHS) and Medical Outcomes Survey 36-item Short Form Health Survey (SF-36).ResultsThe mean LLC (and standard deviation) after CPO was −0.08 ± 3.10 mm. The mean HHS significantly improved from 73.5 points to 91.9 points (P < .001). The physical component and role component scores of SF-36 significantly improved from 35.1 to 46.1 (P < .001) and from 39.5 to 47.0 (P < .001), respectively. No significant differences were found between the preoperative and postoperative mental component scores of SF-36. In addition, among 70 hips, 35 hips exhibited leg length elongation (0 to plus 6.82 mm) after CPO, whereas 35 hips exhibited leg length shortening (0 to minus 6.23 mm). No significant differences were found in HHS and SF-36 between the leg elongation group and leg shortening group.ConclusionThe mean LLC after CPO was −0.08 ± 3.10 mm, and this change does not affect the postoperative clinical outcomes.     

Oversized Cups as a Major Risk Factor of Postoperative Pain After Total Hip Arthroplasty

After total hip arthroplasty (THA) some patients have persistent postoperative pain (POP). Some of these POP are anterior and are caused by an anterior iliopsoas impingement (AIPI). We have hypothesized that oversized implanted cups could be responsible for POP and especially AIPI. We screened 237 patients who had a primary THA and compared the size difference (ΔS) between the native femoral head and the implanted cup, in patients with and without POP. Median ΔS was 2 mm [− 6; 11 mm] and patients with POP had a significantly increased ΔS (P < 0.0001). The threshold above which pain was significantly more frequent was ΔS ≥ 6 mm. Odds ratio was 14.4 for POP and 26 for AIPI pain when ΔS ≥ 6 mm.     

全髋关节置换术后下肢不等长影响因素的研究

目的 探讨全髋关节置换术后下肢不等长(LLD)的影响因素和控制下肢长度的方法 .方法 回顾性分析124例全髋关节置换术(THR)患者的影像学资料,利用NEUSOFT PACS/RIS3.0影像诊断系统测量LLD值,并按性别、麻醉方式和年龄分组进行统计学分析.结果 本研究中124例患者THR术后下肢不等长的发生率(LLD绝对值＞10 mm)为21.77%.不同性别、麻醉方式和年龄的患者LLD发生率差别没有统计学意义.不同性别、麻醉方式的患者LLD值差别也无统计学意义.年龄＜65岁组年轻患者LLD值=(3.7091±6.51886)mm,年龄≥65岁组的老年患者LLD值=(-0.0736±8.31605)mm,差异有统计学意义(P＜0.05).结论 通过使用NEUSOFTPACS/RIS3.0影像诊断系统辅助术前模板测量,可以达到降低THR术后LLD的发生率的目的 .年龄＜65岁组比年龄≥65岁组的患者手术侧下肢长度偏长.