Patients' perception of pain after total hip arthroplasty

A Study of Tibial Cyst Formation in Modular Stemmed Total Ankle Arthroplasty: Exploring a Possible Relationship to Smooth and Porous Coating on the Stem Segments

Vertical fixation through stemmed components has been a successful strategy in total ankle arthroplasty. Research in hip replacement surgery has demonstrated increased rates of stress shielding, aseptic loosening, thigh pain, and cystic formation around stemmed femoral implants extensively coated with porous surfaces. While some ankle prostheses have integrated porous coating technology with stemmed tibial implants, there is little to no research investigating the potential negative effects of bone bonding to the tibial stems and possible impact on tibial cyst formation. We performed a retrospective cohort study comparing the incidence of periprosthetic tibial cyst formation in smooth versus fully porous-coated stemmed tibial implants after undergoing total ankle implant arthroplasty. Radiographs were compared for postoperative rates of tibial cyst formation and bone bonding to the tibial stems. Relative risk for reoperation between the smooth and porous-coated implants was investigated. The smooth-stem group showed no incidence of tibial cyst formation nor signs of significant bone bonding to the tibial stems; however, the follow-up matched porous-coated group showed a rate of 63% of cystic formation with associated evidence of bone bonding on final radiographic follow-up (p < .01). Relative risk for reoperation was 0.74. Despite a higher incidence of tibial cyst formation in the stemmed ankle arthroplasty groups with porous coating, reoperation rates were similar. We theorize that the proximal bonding to the porous stem surface could impact the distal stems and result in the observed increase in cyst formation.

The role of 3-dimensional preoperative planning for primary total hip arthroplasty based on artificial intelligence technology to different surgeons: A retrospective cohort study

Preoperative planning with computed tomography (CT)-based 3-dimensiona (3D) templating has been achieved precise placement of hip components. This study investigated the role of the software (3-dimensional preoperative planning for primary total hip arthroplasty [THA] based on artificial intelligence technology, artificial intelligence hip [AIHIP]) for surgeons with different experience levels in primary THA. In this retrospective cohort study, we included patients, who had undergone THA with the help of the AIHIP, and matched to patients, who had undergone THA without the help of the AIHIP, by age and the doctor who operated on them. The subjects were divided into 4 groups, senior surgeon (Chief of Surgery) with AIHIP group, senior surgeon without AIHIP group, junior surgeon (Associate Chief of Surgery) with AIHIP group and junior surgeon without AIHIP group. The general data, imaging index, clinical outcomes and accuracy of stem size prediction and cup size prediction were retrospectively documented for all patients. There was a significant difference in discrepancy in leg length (P = .010), neck-shaft angle (P = .025) and femoral offset (P = .031) between the healthy side and the affected side, operation duration (P < .001), decrease in hemoglobin (Hb) per 24 hours (P = .046), intraoperative radiation exposure frequency (P < .050) and postoperative complications (overall P = .035) among the patients in junior surgeon group. No significant differences were found between senior surgeon groups with respect to discrepancy in leg length (P = .793), neck-shaft angle (P = .088)and femoral offset (P = .946) between the healthy side and the affected side, operation duration (P = .085), decrease in Hb per 24 hours (P = .952), intraoperative radiation exposure frequency (P = .094) and postoperative complications (overall P = .378). The stem sizes of 95% were accurately estimated to be within 1 stem size, and 97% of the cup size estimates were accurate to within 1 cup size in senior surgeon group with AIHIP. A total of 87% stem sizes were accurately estimated to be within 1 stem size, and 85% cup sizes were accurate to within 1 cup size in junior surgeon group with AIHIP. In conclusion, our study suggests that an AI-based preoperative 3D planning system for THA is a valuable adjunctive tool for junior doctor and should routinely be performed preoperatively.

Periprosthetic Occult Femoral Fracture: An Unknown Side Effect of Press-Fit Fixation in Primary Cementless Total Hip Arthroplasty

Purpose

The objectives of this study were to examine the prevalence and risk factors for development of periprosthetic occult femoral fractures during primary cementless total hip arthroplasty (THA) and to assess the clinical consequences of these fractures.

Materials and Methods

A total of 199 hips were examined. Periprosthetic occult femoral fractures were defined as fractures not detected intraoperatively and on postoperative radiographs, but only observed on postoperative computed tomography (CT). Clinical, surgical, and radiographic analysis of variables was performed for identification of risk factors for periprosthetic occult femoral fractures. A comparison of stem subsidence, stem alignment, and thigh pain between the occult fracture group and the non-fracture group was also performed.

Results

Periprosthetic occult femoral fractures were detected during the operation in 21 (10.6%) of 199 hips. Of eight hips with periprosthetic occult femoral fractures that were detected around the lesser trochanter, concurrent periprosthetic occult femoral fractures located at different levels were detected in six hips (75.0%). Only the female sex showed significant association with an increased risk of periprosthetic occult femoral fractures (odds ratio for males, 0.38; 95% confidence interval, 0.15-1.01; P=0.04). A significant difference in the incidence of thigh pain was observed between the occult fracture group and the non-fracture group (P<0.05).

Conclusion

Occurrence of periprosthetic occult femoral fractures is relatively common during primary THA using tapered wedge stems. We recommend CT referral for female patients who report unexplained early postoperative thigh pain or developed periprosthetic intraoperative femoral fractures around the lesser trochanter during primary THA using tapered wedge stems.

Effects of changes in whole-body alignment on ipsilateral knee pain after total hip arthroplasty

BACKGROUND

Total hip arthroplasty decreases hip pain and often reduces knee pain in patients with hip osteoarthritis. Whole-body alignment may be associated with knee pain, but to our knowledge this relationship has not been previously investigated. The purpose of this study was to investigate the effect of changes in whole-body alignment on ipsilateral knee pain in patients after total hip arthroplasty.

METHODS

In total, 94 patients with unilateral hip osteoarthritis who underwent total hip arthroplasty were enrolled in this study. A visual analog scale (VAS) was used to investigate perioperative knee pain. An EOS 2D/3D X-ray system was used to quantify the whole-body alignment of the spine, pelvis, and lower extremities in the standing position. The relationship between perioperative changes in knee pain and whole-body alignment was investigated.

RESULTS

Among 61 patients who had preoperative ipsilateral knee pain, pain resolved in 30 (50%) and persisted in 31 (50%) after surgery. In these patients, average ipsilateral knee pain decreased significantly after surgery, from 41 mm to 14 mm on the VAS (P < 0.01). Preoperative knee pain was correlated with femorotibial rotation, and postoperative knee pain was correlated with K-L grade, preoperative knee pain visualized analog scale, and preoperative sagittal vertical axis. Multiple linear regression identified preoperative sagittal vertical axis as significantly associated with residual postoperative ipsilateral knee pain.

CONCLUSIONS

Ipsilateral knee pain decreased in half of patients after total hip arthroplasty. Patients with a considerable forward-bent posture may have residual ipsilateral knee pain after total hip arthroplasty.

Differences in peri-hip articular pain after total hip arthroplasty between taper wedge stem and fit-and-fill stem

Background

Total hip arthroplasty (THA) for hip disorders helps to alleviate pain and improve active daily life. When determining the effects of medical therapy and the subsequent clinical results, patient quality of life (QOL) also needs to be assessed. Recently, patient-reported outcomes (PRO) have become important as evaluation criteria. This study aimed to evaluate patient QOL and various PRO between different types of cementless stems and to clarify the relationship between PRO and stem-cortical bone contact.

Methods

The study comprised 138 consecutive patients undergoing cementless THA for hip osteoarthritis. We assessed three different types of PRO: the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), patient's joint perception, and peri-hip articular joint pain (PHAP). We measured the state of contact between femur and implant by density mapping.

Results

No significant difference was noted in PRO between stem types based on the JHEQ and patient's joint perception. PHAP occurred more frequently in the patients with a taper wedge stem versus a fit-and-fill stem. In both groups, distal contact was associated with PHAP but not with JHEQ results and patient's joint perception.

Conclusion

The difference in PHAP between the two stem types groups was significant, with postoperative PHAP being higher with the taper wedge stem because of the more distal contact between the taper wedge stem and femur cortical bone.

The short-term outcomes of cementless stem for hip arthroplasty in the elderly patients: comparison with patients < 65 years

OBJECTIVE

The use of cement or cementless femoral stem prosthesis for hip arthroplasty in elderly patients has been controversial. This study investigated the efficacy and safety of cementless femoral stem in elderly patients (age ≥ 65 years).

METHODS

The short-term efficacy of primary hip arthroplasty with cementless femoral stem in our hospital from January 2014 to June 2021 was retrospectively analyzed. Patients were divided into two groups according to age: young group (< 65 years) and the elder group (≥ 65 years). The evaluation index was the Harris Hip score (Harris), postoperative femoral stem prosthesis sinking distance and femoral plant-related complications (periprosthetic fracture, prosthesis loosening, infection, dislocation, etc.).

RESULTS

There were 72 cases of 86 hips in the young group and 83 cases of 92 hips in the elder group. The recovery trend of functional score in the elder group was similar to that in the young group, and the Harris score increased from (38.35 ± 18.21) before surgery to (86.91 ± 12.55) at last follow-up (p < 0.01). Compared with the two groups at the same time of 3 months, 6 months and 12 months after operation, the sinking distance of the elder group was significantly greater (P < 0.05). Even in the elder group, there was a significant difference in sinking distance between 6 and 3 months after surgery (2.44 ± 0.49 mm vs 2.10 ± 0.65 mm, P = 0.004). However, there was no significant difference between 12 and 6 months (2.53 ± 0.53 mm vs 2.44 ± 0.49 mm, P = 0.40). A total of 10 patients in the elder group and 6 patients in the young group had a complication event (P = 0.36).

CONCLUSIONS

Elderly patients with cementless femoral stems can achieve metal-bone integration slightly longer than young patients, but short-term clinical outcomes can be restored to a satisfactory level with adequate safety. However, the long-term efficacy still needs to be verified by multicenter, large sample size and prospective clinical follow-up results.

The Effect of Femoral Head Size on Groin Pain in Total Hip Arthroplasty

BACKGROUND

Although increased femoral head size reduces the risk of instability in total hip arthroplasty (THA), it may lead to iliopsoas irritation and increased anterior groin pain. The purpose of this study is to compare outcomes between non-modular dual-mobility (NDM) implants and small (≤32 mm) and large (≥36 mm) fixed-bearing (FB) constructs.

METHODS

A retrospective review of all primary total hip arthroplasties from 2011 to 2021 was conducted at a single, urban academic institution. Patients were separated into 3 cohorts: NDM implant ≤32 mm and FB implant ≥36 mm. Demographics and outcomes such as length of stay, dislocation, and anterior groin pain were assessed. Patients were deemed as having groin pain if they received an iliopsoas injection or had extended physical therapy ordered beyond 3 months postoperatively.

RESULTS

There were 178 NDM implants, 936 ≤32-mm FB, and 2,454 ≥36-mm FB implants included. Length of stay significantly differed between the groups (48.4 ± 43.3 vs 63.2 ± 40.6 vs 57.2 ± 38.1 hours; P = .001). Although not statistically significant, the ≥36-mm FB cohort had the highest rate of dislocations (0.6% vs 0.7% vs 0.9%; P = .84). Although no patients with an NDM implant received an iliopsoas injection, 9 patients (0.9%) with a ≤32-mm FB implant and 9 patients (0.4%) with a ≥36-mm implant received an injection (P = .06). However, 18 (10.1%) patients with an NDM implant, 304 (32.5%) patients with a ≤32-mm FB implant, and 355 (14.5%) patients with a ≥36-mm FB implant received extended physical therapy 3 months after surgery (P < .001).

CONCLUSION

NDM implants, as well as FB implants with both small and large head sizes are effective at preventing dislocation. NDM implants did not result in an increase in anterior groin pain compared to ≤32-mm and ≥36-mm FB constructs.

LEVEL III EVIDENCE

Retrospective cohort study.

The relationship between pre-operative pain characteristics and periacetabular osteotomy outcomes in patients with acetabular dysplasia

The aims of this study were to determine if pre-operative pain characteristics (location of maximum severity of pain, presence of non-groin pain, maximum severity of pain and number of pain locations) affect patient-reported outcome measures in patients undergoing periacetabular osteotomy (PAO) for acetabular dysplasia. We reviewed 52 hips (48 patients) treated with PAO for acetabular dysplasia from February 2017 to July 2020 using modified Harris Hip Score (mHHS), Hip Outcome Score (HOS) and international Hip Outcome Tool (iHOT-12) score, radiographic analysis and pain location/severity questionnaires. Descriptive statistics, analysis of covariance and Spearman partial correlation coefficients were implemented. Twenty-six hips experienced the most severe pre-operative pain in the groin, and 26 hips experienced equal or greater pain in a non-groin location. Outcome scores between these groups were not significantly different (mHHS P = 0.59, HOS P = 0.48, iHOT-12 P = 0.99). Additionally, the presence of pre-operative pain in any non-groin location had no significant relationship with PROM (all P-values ≥0.14). Furthermore, the maximum severity of pre-operative pain and number of pain locations showed no significant relationship with PROM (maximum severity: mHHS P = 0.82, HOS P = 0.99, iHOT-12 P = 0.36; number of pain locations: mHHS P = 0.56, HOS P = 0.10, iHOT-12 P = 0.62). Varying pre-operative pain characteristics do not appear to have any significant impact on outcomes. Therefore, a wide array of patients with acetabular dysplasia might expect similar, favourable outcomes from PAO regardless of pre-operative pain characteristics.

Comparison of tapered-wedge short and standard-length femoral stems in single-stage bilateral direct anterior total hip arthroplasty

PURPOSE

This study was performed to compare short and standard-length tapered-wedge-type femoral stems in single-stage bilateral total hip arthroplasty (THA) through a direct anterior approach (DAA).

MATERIALS AND METHODS

The patients were divided into two groups according to their femoral stem types as short tapered-wedge stem and standard-length tapered-wedge stem groups. Outcome parameters were the surgical time, estimated blood loss (EBL), length of stay (LOS), thigh pain, Harris Hip Score (HHS), and visual analog scale (VAS) score clinically, and canal fill ratio (CFR), coronal plan alignment of the stems, subsidence, and postoperative leg length difference (LLD), radiologically.

RESULTS

The short-stem group and standard-length-stem group consisted of 20 patients (40 hips, mean age 52.0 ± 14.1) and 22 patients (44 hips, mean age 49.4 ± 11.9), respectively. There were no significant differences between the groups in terms of mean surgical times (p = 0.6), EBL (p = 0.2), LOS (p = 0.2), the rate of thigh pain (p = 0.4), improvements in HHS (p = 0.4) and VAS scores (p = 0.6), LLD (p = 0.3), amount of subsidence (p = 0.9), and varus or valgus misalignment (p = 0.7). The CFR at the level of the lesser trochanter was significantly higher in the short-stem group (0.79 ± 0.1) than the standard-length-stem group (0.73 ± 0.1) (p < 0.01).

CONCLUSION

In single-stage bilateral THA through DAA, short, tapered-wedge femoral stems provide similar radiographic and functional results to standard stems at short-term follow-up.

Distal femoral cortical hypertrophy not associated with thigh pain using a short stem femoral implant

BACKGROUND

Thigh pain following a well-fixed total hip arthroplasty (THA) remains problematic and a source of patient dissatisfaction. The purpose of this study is to evaluate if the development of distal femoral cortical hypertrophy (DFCH) is associated with postoperative thigh pain after THA.

METHODS

All patients who underwent an uncomplicated primary THA via a direct anterior approach with the Taperloc Microplasty (Zimmer Biomet, Warsaw, IN, USA) implant between 2011 and 2015 were mailed a pain drawing questionnaire. Radiographs were reviewed at 1 year minimum to determine cortical thickness change from immediate post-op. Thigh pain was compared to DFCH. 293 patients were included in the study.

RESULTS

Mean follow-up was 3.2 years. A total of 218 hips (74%) had cortical hypertrophy in Gruen zone 3 and 165 hips (56%) had cortical hypertrophy in Gruen zone 5. 52 hips (18%) had ⩾25% cortical hypertrophy in zone 3 and 91 hips (31%) had ⩾25% cortical hypertrophy in zone 5. A total of 44 patients (15%) reported anterior thigh pain and 43 patients (15%) reported lateral thigh pain. Development of DFCH in either Gruen zone 3 or 5 was not associated with anterior or lateral thigh pain. Stem size was positively correlated with zone 3 hypertrophy and inversely related to zone 5 hypertrophy. Thigh pain was not associated with patient age, gender, activity level or stem size.

CONCLUSIONS

The development of distal femoral cortical hypertrophy after THA with a short stem implant was high, but not associated with patient-reported anterior or lateral thigh pain.

No Clinically Important Differences in Thigh Pain or Bone Loss Between Short Stems and Conventional-length Stems in THA: A Randomized Clinical Trial

BACKGROUND

Short-length stems were developed to reduce bone loss of the proximal femur and potentially decrease the incidence of thigh pain after cementless THA. However, it remains unknown whether short stems indeed reduce bone loss or the frequency of thigh pain.

QUESTIONS/PURPOSES

Is there a difference between short- and standard-length stems in terms of: (1) the frequency or severity of thigh pain, (2) modified Harris hip scores, (3) implant loosening, or (4) bone mineral density as measured by dual-energy x-ray absorptiometry?

METHODS

Between March 2013 and January 2014, three surgeons performed 205 primary THAs. To be eligible, patients needed to be at least 20 years of age, have not undergone previous history of hip surgery, and have no metabolic bone disease. A total of 100 patients were randomized to receive THA either with a short stem (n = 56) or with a standard-length stem (n = 44). Both stems were proximally coated, tapered, cementless stems. Compared with standard stems, short stems typically were 30- to 35-mm shorter. A total of 73% (41 of 56) and 77% (34 of 44) of those groups, respectively, were accounted for at a minimum of 5 years and were analyzed. The presence of thigh pain during activity was evaluated using a 10-point VAS, and the modified Harris hip score was calculated by research assistants who were blinded to the treatment groups. Plain radiographs were taken at 6 weeks, 6 months, and 12 months postoperatively, and every 1 year thereafter; loosening was defined as subsidence > 3 mm or a position change > 3° on serial radiographs. Radiological assessment was performed by two researchers who did not participate in the surgery and follow-up evaluations. Bone mineral density of the proximal femur was measured using dual-energy x-ray absorptiometry at 4 days, 1 year, 2 years, and 5 years postoperatively. The primary endpoint of our study was the incidence of thigh pain during 5-year follow-up. Our study was powered at 80% to detect a 10% difference in the proportion of patients reporting thigh pain at the level of 0.05.

RESULTS

With the numbers available, we found no difference between the groups in the proportion of patients with thigh pain; 16% (9 of 56) of patients in the short-stem group and 14% (6 of 44) of patients in the standard-stem group experienced thigh pain during the follow-up period (p = 0.79). In all patients, the pain was mild or moderate (VAS score of 4 or 6 points). Among the 15 available patients who reported thigh pain, there was no difference between the implant groups in mean severity of thigh pain (4.3 ± 0.8 versus 4.2 ± 0.7; p = 0.78). There were no between-group differences in the short versus standard-length stem groups in terms of mean modified Harris hip score by 5 years after surgery (89 ± 13 versus 95 ± 7 points; p = 0.06). No implant was loose and no hip underwent revision in either group. Patients in the short-stem group showed a slightly smaller decrease in bone mineral density in Gruen Zones 2, 3, and 5 than those in the standard-stem group did; the magnitude of the difference seems unlikely to be clinically important.

CONCLUSION

We found no clinically important differences (and few differences overall) between short and standard-length THA stems 5 years after surgery in a randomized trial. Consequently, we recommend that clinicians use standard-length stems in general practice because standard-length stems have a much longer published track record in other studies, and short stems can expose patients to the uncertainty associated with novelty, without any apparent offsetting benefit.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Mid-term results of short versus conventional cementless femoral stems in patients with bilateral osteonecrosis of the femoral head

BACKGROUND

This study aimed to compare the clinical and radiographic mid-term results between short and conventional stems.

METHODS

Patients with bilateral osteonecrosis of the femoral head (ONFH) who had undergone bilateral staged THAs using short stem in one hip and conventional stem in the contralateral hip were included. The Harris Hip Score (HHS), thigh pain, patient's joint perception (PJP) and patients' preferred hip were recorded. Using x-ray, osseointegration and stress shielding were analyzed and compared between stems.

RESULTS

There were 35 cases (70 hips) with the mean age of 46.3 years (25-63), and the mean follow-up was 75.1 months (60-108). HHS was significantly improved in both short and conventional groups (p < 0.001). There was mild thigh pain in 2 cases (5.7%) of the short stem group and 6 cases (17.1%) of the conventional group. With regard to the PJP, we found slightly more natural joint feeling in the short stem group. Of the patients' preferred hip, 11 cases (31.4%) preferred short stem hip and 6 cases (17.1%) preferred conventional stem hip. The short stem group showed osseointegration mainly in the proximal part. The conventional stem group showed osseointegration mainly in the distal part. We found stress shielding grade 1 in 31 cases (88.6%) and grade 2 in 3 cases (8.6%) in the conventional stem group, whereas only grade 1 in 34 cases (97.1%) in the short stem group.

CONCLUSIONS

The clinical results were promising in both short and conventional stems; however, short stem showed less thigh pain, slightly more natural joint feeling (PJP) and more patients' preferred hip. The short stem provided more favorable results for proximal load transfer and slightly less stress shielding.

The use of density mapping in the analysis of thigh pain after total hip arthroplasty in patients with well-fixed tapered wedge stems

PURPOSE

The mechanisms underlying thigh pain in patients with well-fixed cementless femoral components after total hip arthroplasty (THA) remains unclear. We hypothesized that the thigh pain is correlated with the initial contact state of the stem and aimed to investigate the relation between thigh pain and the initial contact state.

MATERIALS AND METHODS

A total of 209 hips of 184 patients were analysed in this retrospective case-control study. The patients were divided into a thigh pain group (n = 13 hips) and a control group (without thigh pain, n = 196). Post-operative stem contact images were three-dimensionally visualized by a density mapping function using computed tomography data, which quantified the stem contact area according to Gruen zones. Thigh pain was defined as anterior or anterolateral pain upon loading at 3-month post-operatively.

RESULTS

Thirteen hips (6.2%) had thigh pain; however, all the hips demonstrated stable bony ingrowth radiographically. The thigh pain group had a significantly lower contact area in zone 2 (p = 0.014). The multivariate logistic regression analysis showed that the contact area of zone 2 was negatively correlated with thigh pain [odds ratio (OR): 0.858, p = 0.018], and the canal flare index was negatively correlated with the development of thigh pain (OR: 0.336, p = 0.026).

CONCLUSIONS

We identified an association between the initial contact state and post-operative thigh pain. Our data demonstrated that proper lateral contact prevents the occurrence of thigh pain in THA using a tapered wedge stem.

Malalignment and distal contact of short tapered stems could be associated with postoperative thigh pain in primary total hip arthroplasty

PURPOSE

Short tapered stem placement has been extensively employed in total hip arthroplasty (THA). Suboptimal fixation tends to cause postoperative complications, such as thigh pain. However, it remains unclear whether poor seating/alignment of short tapered stems contributes to thigh pain. In this study, we retrospectively examined the factors that might be associated with thigh pain.

METHODS

Medical records of 230 patients who had undergone THAs at our hospital were reviewed retrospectively. All patients received the same mediolateral (ML) short tapered femoral stems. The association between thigh pain and patients' demographics, radiographic findings, or the type of fitting of the femoral stems was investigated.

RESULTS

In our cohort, 68 patients (27.8%) presented with thigh pain. Among 203 type I fit patients, 62 (30.5%) developed thigh pain, while only 6 out of 43 (12.2%) type II fit patients had thigh pain, with the differences being statistically significant (x² = 6.706, p = 0.01). In addition, hip anteroposterior radiographs exhibited that the stem angulation (mean 2.52°), the variation in angulation (mean 1.32°), and the extent of femoral stem subsidence (mean 0.29 cm) were greater in patients with thigh pain than in their counterparts without thigh pain (all p < 0.05).

CONCLUSION

Malalignment and improper seating of short tapered stems could be at least one of the reasons for post-THA thigh pain. The distal contact between the stem tip and the medial femoral cortex might result in thigh pain. Our study suggested that distal implant contact should be avoided, and stem alignment should be meticulously performed in the placement of ML short tapered femoral stems for THA.

Use of a Constrained Acetabular Liner to Prevent and Treat Recurrent Dislocation after Total Hip Replacement Arthroplasty

The aim of the present study was to evaluate the dislocation rate and the risk factors leading to instability after primary and revision total hip replacement arthroplasty (THRA) with constrained acetabular liners (CAL), as well as treatment strategies for prevention of dislocation. From 1999 to 2017, drawing on two institutions' THRA registries, we retrospectively identified 46 THRA cases using a CAL that had been followed up for a minimum of 4 years. The patients comprised 39 women and 7 men, with an average age of 69.1 years (age range, 41-98). Of the 46 patients, CAL were used in 12 patients for prevention of dislocation in primary THRA and in 34 patients for treatment of recurrent dislocation after primary THRA. Clinical and radiological evaluation were performed. We evaluated the failure rate of CAL as well as the risk factors. The 12 patients who used CAL for prevention of dislocation in primary THRA had no dislocation. However, 12 (35%) of the 34 hips had a dislocation after use of CAL in revision THRA. Patients with an abductor muscle weakness grade of ≤3 had a higher rate of dislocation than those with a grade of ≥4 (grade 1; likelihood ratio = ∞, grade 2; likelihood ratio = 1.83, grade 3; likelihood ratio = 1.05, grade 4; likelihood ratio = 0.46, and grade 5; likelihood ratio = 0). The group of primary THRA with CAL had no dislocations, and this is a proper way for prevention of dislocation in high-risk patients. The group of revision THRA with CAL had a high dislocation rate (35%). Abductor muscle weakness below grade 3 was a risk factor for failure of CAL for hip dislocation. We recommend treating patients with recurrent dislocations with the presence of abductor muscle weakness below grade 3 with not only THRA using CAL but also applying additional abductor muscle reconstruction to reduce the risk of dislocation.

Outcomes with Two Tapered Wedge Femoral Stems in Total Hip Arthroplasty Using an Anterior Approach

Background

The majority of hip arthroplasties in the United States utilize cementless acetabular and femoral components. Despite their similarities, stem geometry can still differ. The purpose of this study is to compare the clinical results of two wedge-type stem designs.

Methods

A retrospective study of patients who underwent primary THA utilizing a direct anterior approach between January 2016 and January 2017. Two cohorts were established based on femoral stem design implanted. Descriptive patient characteristics and surgical and clinical data was extracted which included surgical time, length of stay (LOS), presence of pain (categorized as groin, hip, or thigh pain) at the latest follow-up, and revisions. Immediate postoperative radiographs were compared with the latest follow-up radiographs to assess limb length discrepancies, stem alignment, and stem subsidence.

Results

A total of 544 patients were included. 297 patients received the Group A stem (morphometric) and 247 patients received the Group B stem (flat-tapered). A significantly higher proportion of Group B stems subsided ≥3 mm and were in varus alignment than the Group A design. Additionally, a significantly greater number of patients who received the Group B stem reported postoperative hip and thigh pain. The logistic regression found that the Group B stem was 2.32 times more likely to subside ≥3 mm than the Group A stem.

Conclusion

Our study suggests modestly improved radiographic and clinical outcomes and fewer instances of thigh pain, subsidence, and varus alignment in the patients who received the Group Ahip stem. Further studies are warranted to assess long-term significance.

Risk factors of thigh pain following total hip arthroplasty with short, tapered-wedge stem

PURPOSE

The occurrence of thigh pain following cementless total hip arthroplasty (THA) may be dependent on multiple factors, which may differ with design of the prosthesis. Thus, this study aimed to investigate the frequency of thigh pain following cementless THA using a short, tapered-wedge stem to identify risk factors for thigh pain.

METHODS

This retrospective cohort study analysed 222 joints of patients who underwent THA with a short, tapered-wedge stem. Thigh pain was evaluated using a questionnaire during each follow-up visit, and the clinical and radiographic assessments were compared.

RESULTS

Thigh pain occurred in 37 patients (16.7%) during the follow-up period. The pain started two to 24 months after THA. Multivariate analysis demonstrated that higher University of California, Los Angeles, activity rating (odds ratio 7.2; 95% confidence interval (CI) 3.0-17.2); Dorr type C femoral bone shape (odds ratio 1.5; 95% CI 1.1-2.0); and stem tip-cortical bone contact (odds ratio 8.2; 95% CI 2.3-29.4) were significant risk factors of thigh pain following THA. Post-operatively, cortical hypertrophy at Gruen zone 4 was significantly found in patients with thigh pain (p value = 0.032).

CONCLUSION

Risk factors of pain following THA with short, tapered-wedge stem were high activity level, Dorr type C femoral bone shape, and stem tip contacting the distal bone surface. Moreover, post-operative cortical hypertrophy at the distal stem tip significantly increased the incidence of thigh pain. Therefore, we must pay attention to the aforementioned factors to avoid post-operative thigh pain when using a short, tapered-wedge stem.

Association of Femoral Rotation With Whole-Body Alignment in Patients Who Underwent Total Hip Arthroplasty

Background

Although rotational changes in lower limb alignment after total hip arthroplasty (THA) affect functional stem anteversion, less is known about the effects of femoral rotational alignment in the standing position. This study investigated postoperative changes in femoral rotation and evaluated the association with whole-body alignment in patients who underwent THA.

Methods

Sixty-five patients with unilateral hip osteoarthritis who underwent THA were enrolled. Preoperative and postoperative femoral rotation in the standing and supine positions were measured using EOS 2D/3D X-ray imaging system and computed tomography. Negative and positive changes in femoral rotation angle were indicative of internal and external rotation, respectively. The associations between femoral rotation and preoperative clinical and radiological factors were investigated.

Results

Femoral rotation showed significant internal changes in both the standing (-4.7° ± 11.0°) and supine (-3.5°± 10.9°) positions after THA. The preoperative femoral rotation angle, knee flexion angle, sagittal vertical axis (SVA), lumbar lordosis, body mass index, age, and internal and external rotation angles of the hip range of motion on the contralateral side were significantly correlated with femoral rotation in the standing position after THA. Multiple regression analysis showed that preoperative femoral rotation (β = 0.416, P < .001) and SVA (β = 0.216, P = .040) were significant predictors of postoperative femoral rotation in the standing position.

Conclusions

Femoral rotation had significant association with the patient-inherent posture represented by the SVA in the standing position. Because extensive external change of femoral rotation may increase the risk of hip impingement and dislocation, careful attention is required in patients with external femoral rotation and forward bent posture in the preoperative standing position.

The direct superior approach versus posterior approach for total hip arthroplasty: study protocol for a prospective double-blinded randomised control trial

Background

The direct superior approach (DSA) is a minimally invasive modification of the posterior approach (PA) that preserves the iliotibial band and short external rotators except for the piriformis or conjoint tendon during total hip arthroplasty (THA). The objective of this study is to compare patient satisfaction, functional outcomes, accuracy of implant positioning, component stability, gait, cost-effectiveness, and complications in the DSA versus PA for THA.

Methods and analysis

This prospective double-blinded randomised control trial will include 80 patients with symptomatic hip osteoarthritis undergoing primary THA. Following informed consent, patients will be randomised to THA using the PA (control group) or DSA (investigation group) at a ratio of 1:1 using an online random number generator. Blinded observers will review patients at regular intervals for 2 years after surgery to record predefined study outcomes relating to postoperative rehabilitation, clinical progress, functional outcomes, accuracy of implant positioning, gait analysis on force plate treadmill, implant migration with radiosteriometric analysis, cost-effectiveness, and complications. A superiority study design will be used to evaluate whether the DSA provides improved outcomes compared to the PA for THA. Evaluation of study outcomes in DSA and PA will be used to quantify and draw inferences on differences in the efficacy of treatment between the two groups. Intention-to-treat and per-protocol population analysis will be undertaken. The following statistical methods will be employed to analyse the data: descriptive statistics, independent t test, paired t test, analysis of variance, Fisher exact test, chi-square test, and graphical displays. Ethical approval was obtained from the London-Fulham Research Ethics Committee, UK. The study is sponsored by University College London, UK.

Discussion

This study compares a comprehensive and robust range of clinical, functional, and radiological outcomes in THA performed using the PA versus DSA. The findings of this study will provide an improved understanding of the differences in the PA versus DSA for THA with respect to patient satisfaction, functional outcomes, implant survivorship, gait, cost-effectiveness, and complications.

Trial registration

ClinicalTrials.gov, NCT04191993. Registered on 10 December 2019

Comparison of Bone Preservation in Elderly Patients with Femoral Neck Fracture After Bipolar Hemiarthroplasty Using Shorter Femoral Stem and Standard Femoral Stem

BACKGROUND

This randomized control study was designed to compare the clinical and radiological outcomes, including periprosthetic bone mineral density (BMD) changes, between the short and standard stems after using cementless hemiarthroplasty in elderly patients with femur neck fractures.

MATERIALS AND METHODS

From January 2013 to May 2017, 151 patients (aged ≥ 65 years) underwent hemiarthroplasties due to femoral neck fractures. Patients were randomized into two groups; 77 patients in Group A implanting the short femoral stem and 74 patients in Group B implanting the standard femoral stem. Clinical and radiographic evaluations were performed in all patients.

RESULTS

75 patients (40 patients in Group A and 35 patients in Group B) completed routine follow-up for a minimum of 2 years. The clinical outcomes, including ambulatory functions and thigh pain, were similar in both groups. All the femoral stems acquired radiologic stability. At postoperative one year, BMD values in Gruen zone (G) seven on the standard stem side were significantly lower than those on the short stem side (P = 0.038). At the second year of follow-up, the BMD values of Group A in G1, G3, G4, and G7 were significantly greater than those of Group B (P = 0.007, 0.032, 0.026, and P < 0.000, respectively).

CONCLUSIONS

Both the clinical outcomes and radiologic stability in both group demonstrated similar results in elderly patients with femoral neck fracture at the latest follow-up. In addition, the periprosthetic BMD of the short femoral stems demonstrated better periprosthetic bone preservation at a minimum of 2 years of follow-up.

LEVEL OF EVIDENCES

Therapeutic Level II.

Minimum 15-Year Results of a Dual-Offset Uncemented Femoral Stem in Total Hip Arthroplasty

BACKGROUND

The aim of the present study is to assess the long-term clinical and radiological outcomes of a proximal porous-coated, dual-offset, tapered titanium alloy uncemented stem at a minimum of 15 years of follow-up.

METHODS

We reviewed 210 total hip arthroplasties (in 193 patients) performed between 1996 and 1999 and followed prospectively in our database who received the Synergy stem. We report a Kaplan-Meier survival analysis as well as the Harris Hip Score, the Western Ontario and McMaster University Arthritis Index, and the Short Form Health Survey-12 scores. Radiographs were evaluated for evidence of subsidence, osteolysis, osteointegration, or loosening.

RESULTS

The average follow-up was 16 years (range, 15-17.7 years). Kaplan-Meier survival analysis with revision of stem for aseptic mechanical loosening (1 stem) as the end point revealed a cumulative survival rate of 99.5% at 16 years. The Harris Hip Score, the Western Ontario and McMaster University Arthritis Index, and the Short Form Health Survey-12 physical scores were all significantly improved (P < .001) from the preoperative period to latest follow-up. Minor osteolysis was observed proximally in 14 hips (6.6%) with no osteolysis distal to the porous coating.

CONCLUSION

To our knowledge, this study represents the largest series reporting the longest clinical follow-up of this third-generation, dual-offset, proximal ingrowth, tapered cementless stem. The Synergy stem design has achieved excellent clinical outcomes, predictable osteointegration, and outstanding survivorship of 99.5% at a minimum of 15 years follow-up, representing the standard for femoral stems at our institution.

Correlation between anterior thigh pain and morphometric mismatch of femoral stem

BACKGROUND

Postoperative pain occurring after hip arthroplasty has become common since the expanded use of cementless femoral stems. The characteristic pain develop in the anterolateral thigh area. This study aimed to predict anterior thigh pain based on the measurements of postoperative anteroposterior (AP) and lateral (Lat) radiographs of the hip joint.

METHODS

The present study included 26 patients (29 hips) who underwent total hip replacement or bipolar hemiarthroplasty between March 2010 and May 2016, whose complete clinical information was available. AP and Lat radiographs of the affected hip were taken on the day of surgery and 1 and 6 months postoperatively. Patients with improper radiographs were excluded. The distance from the femoral stem to the nearest cortical bone in the distal region of the stem was measured. The patient group with a visual analog scale (VAS) score of ≥6 points was designated as patients with anterior thigh pain.

RESULTS

Sex, age, weight, height, body mass index, and bone mineral density in the lumbar spine and femur did not have a significant effect on postoperative VAS scores (p>0.05). Presence of contact between the femoral stem and cortical bone was associated with postoperative anterior thigh pain.

CONCLUSION

Hip AP and Lat radiographs are usually taken to confirm fixation and alignment of the femoral stem after hip arthroplasty. The measurement method introduced in this study can be utilized for predicting anterior thigh pain after hip arthroplasty.

Occult periprosthetic femoral fractures occur frequently during a long, trapezoidal, double-tapered cementless femoral stem fixation in primary THA

The present study aimed to investigate the prevalence and clinical consequences of occult intra-operative periprosthetic femoral fractures in total hip arthroplasty (THA). Between 2012 and 2017, a total of 113 primary THAs were enrolled. The mean age of the patients was 66.4 ± 7.6 years. We assessed occult intra-operative periprosthetic femoral fractures with the use of computed tomography (CT) and risk factors, including age, sex, body mass index, diagnosis, stem size, and radiographic parameters of proximal femoral geometry were analyzed. We also assessed the differences in thigh pain and stem subsidence and alignment between the patients with and without occult periprosthetic femoral fracture. Occult intra-operative periprosthetic femoral fractures were found in 13 of 113 hips (11.5%). In 9/13 (69.2%) of occult fractures, fracture lines were started from the region below the tip of the lesser trochanter. Six periprosthetic femoral fractures (5.3%) were found during the operation. Out of the five hips that had detected femoral fractures around the lesser trochanter intra-operatively, four hips (80%) showed concurrent occult fractures on different levels. The female sex (P = .01) and canal filling ratio at 7 cm below the tip of the lesser trochanter (P = .01) were significantly different between the patients with and without occult periprosthetic femoral fracture. The sex was significantly associated with an increased risk in predicting an occult intra-operative periprosthetic femoral fracture (odds ratio of male, 0.25 compared with the female; 95% CI, 0.08-0.85; p = .02). There was a significant difference in the incidence of thigh pain between occult fracture group and non-occult fracture group (P < .05). There were no significant differences in stem subsidence and alignment between the patients with and without occult periprosthetic femoral fracture. All 13 cases of occult intra-operative periprosthetic femoral fractures were healed at the final follow-up. Occult periprosthetic femoral fractures are common during a long, trapezoidal, double-tapered cementless femoral stem fixation in primary THA, that CT scans are helpful to identify them, and that these fractures do not adversely affect the implant's survival if a rigid fixation of the implants has been achieved.

The direct superior approach in total hip arthroplasty

The direct superior approach is a modification of the minimally invasive posterior approach for total hip arthroplasty which preserves the iliotibial band and external rotators except for the piriformis or conjoint tendon. This review explores the existing scientific evidence on clinical, functional and radiological outcomes in total hip arthroplasty performed using the direct superior approach. The direct superior approach reduces iatrogenic periarticular soft tissue injury compared to the direct anterior approach for total hip arthroplasty. The learning curve for the direct superior approach is 40 operative cases with operative times comparable to those of conventional approaches for total hip arthroplasty after surgical proficiency has been achieved. The direct superior approach provides improvements in pain and short-term functional outcomes after total hip arthroplasty as assessed using the Harris Hip Score. The minimally invasive posterior approach provides comparable pain scores and improved University of California, Los Angeles (UCLA) activity scale functional scores to the direct superior approach at 1-year follow up. Existing studies using plain radiographs have shown that the direct superior approach enables accurate femoral and acetabular implant positioning.

Does patient-reported perception of pain differ based on surgical approach in total hip arthroplasty?

Aims

Whether patient-reported pain differs among surgical approaches in total hip arthroplasty (THA) remains unclear. This study’s purposes were to determine differences in pain based on surgical approach (direct anterior (DA) vs posterolateral (PL)) and PL approach incision length.

Patients and Methods

This was a retrospective investigation from two centres and seven surgeons (three DA, three PL, one both) of primary THAs. PL patients were categorized for incision length (6 cm to 8 cm, 8 cm to 12 cm, 12 cm to 15 cm). All patients had cementless femoral and acetabular fixation, at least one year’s follow-up, and well-fixed components. Patients completed a pain-drawing questionnaire identifying the location and intensity of pain on an anatomical diagram. Power analysis indicated 800 patients in each cohort for adequate power to detect a 4% difference in pain (alpha = 0.05, beta = 0.80).

Results

A total of 1848 patients (982 DA, 866 PL) were included. PL patients were younger (59.4 years, sd 12.9 vs 62.7 years, sd 9.7; p < 0.001) and had shorter follow-up (3.3 years, sd 1.3 vs 3.7 years, sd 1.3; p < 0.001). DA patients reported decreased moderate to severe trochanteric (14% vs 21%; p < 0.001) and groin pain (19% vs 24%; p = 0.004) than PL patients. There were no differences in anterior, lateral, or posterior thigh, back, or buttock pain between cohorts (p = 0.05 to 0.7). PL approach incision length did not impact the incidence or severity of pain (p = 0.3 to 0.7).

Conclusion

A significant proportion of patients perceive persistent pain following THA regardless of approach. DA patients reported less trochanteric and groin pain versus PL patients. PL incision length did not influence the incidence or severity of patient-reported pain. Cite this article: Bone Joint J 2019;101-B(6 Supple B):31–36.

Mild Coronal Stem Malalignment Does Not Negatively Impact Survivorship or Clinical Results in Uncemented Primary Total Hip Arthroplasties With Dual-Tapered Implants

BACKGROUND

Proper component positioning in total hip arthroplasty (THA) is crucial for implant fixation and hip stability. The purpose of this study is to assess if neutral coronal stem alignment (0° ± 3°) improved long-term survivorship in uncemented femoral components.

METHODS

Between 2005 and 2010, 1028 primary THAs were performed with 2 contemporary dual-tapered, proximally coated uncemented stem types. Alignment was measured immediately postoperatively and at most recent follow-up. In total, 978 femoral stems (95%) were within 0° ± 3° of the neutral anatomic coronal axis, and the 50 stems (5%) outside that range were considered outliers (3.1° of valgus to 4.8° of varus). Outcomes analyzed included implant survivorship, Harris Hip Scores, and incidence of dislocation. Mean follow-up was 5 years.

RESULTS

Survivorship free of aseptic femoral component loosening was 99.3% and 98.2% at 5 and 8 years in the neutral group vs 100% at 5 and 8 years in the outlier group (P = .98). Survivorship free of femoral component revision for any reason was 99.1% and 97.3% at 5 and 8 years vs 100% at 5 and 8 years, respectively (P = .80). Harris Hip Scores were similar (89 in both groups; P = .84) at most recent follow-up. The incidence of mild to moderate thigh pain was also similar in both groups (6.1% vs 6%, P = .85). The incidence of dislocation was 1.5% at 8 years, and similar between both groups (P = .77).

CONCLUSION

Slight malalignment of contemporary dual-tapered uncemented THA femoral components does not appear to negatively impact survivorship or clinical outcomes, which is in contrast to cemented femoral components.

LEVEL OF EVIDENCE III

Case-control study.

Increased Persistent Mid-Thigh Pain After Short-Stem Compared With Wedge-Shaped Straight-Stem Uncemented Total Hip Arthroplasty at Medium-Term Follow-Up: A Randomized Double-Blinded Cross-Sectional Study

BACKGROUND

Femoral prosthesis design may impact the frequency of mid-thigh pain. We compared current, incidental, and persistent mid-thigh pain between the short-stem, Collum Femoris femur prosthesis, and the wedge shaped straight-stem, Zweymüller femur prosthesis and studied the associations between demographics, radiographic measurements, and mid-thigh pain.

METHODS

We contacted patients from a randomized controlled trial who underwent uncemented total hip arthroplasty (THA) for hip osteoarthritis at a mean follow-up of 44 months (range 24-64 months). Patients were specifically assessed for current (during assessment), incidental (any time postoperatively for >1 week) mid-thigh pain, and persistent (any time postoperatively for >2 years) mid-thigh pain. Furthermore, we used regression analysis to study associations between demographics, radiographic measurements, and mid-thigh pain.

RESULTS

One hundred forty of 150 patients (93%) responded to our assessment. Mean age at the time of operation was 62 years (±7.0). Current mid-thigh pain occurred in 16 patients (23%) in the Collum Femoris Preserving (CFP) group compared with 10 patients (14%) in the Zweymüller group (P = .192). Incidental mid-thigh pain occurred in 24 patients (34%) in the CFP group compared with 15 patients (21%) in the Zweymüller group (P = .090). Persistent mid-thigh pain was found in 13 patients (19%) in the CFP group compared with five patients (7%) in the Zweymüller group (P = .043). Varus malalignment (odds ratio 1.819 [95% confidence interval 1.034-3.200]) and leg lengthening (odds ratio 1.107 per cm lengthening [95% confidence interval 1.026-1.195]) showed significant associations with mid-thigh pain.

CONCLUSIONS

We found more persistent mid-thigh pain after short-stem uncemented THA compared to wedge-shaped straight-stem uncemented THA during medium-term follow-up. Varus malalignment and leg lengthening were associated with mid-thigh pain.

Outcome of short versus conventional stem for total hip arthroplasty in the femur with a high cortical index: a five year follow-up prospective multicentre comparative study

BACKGROUND

The uncemented total hip arthroplasty (THA) has become the choice for many hip surgeons. Although conventional uncemented femoral components have a proven track record, there remain concerns about the rate of thigh pain, proximal stress shielding, and consequent loss of bone stock at revision surgery.

METHODS

Inclusion criteria were the following: patients between 50 and 85 years old undergoing primary THA with implant of short (group 1) or conventional (group 2) femoral stem and with femoral shape type A, according to Dorr classification. Clinical follow-up was registered using OHS, HHS, and Womac scores. The radiographic scans were evaluated in order to compare component positioning and bone remodeling at five year follow-up.

RESULTS

We included in the analysis 60 subjects in group 1 and 67 in group 2. No differences were registered between the groups comparing demographic and operative data. One case in group 1 (1.7%) and three cases in group 2 (4.5%) reported an intra-operative fracture. There was a significant improvement in the functional scores in both groups with no significant difference at final follow-up. The incidence of reported thigh pain at follow-up was 14.9% in group 2 and 3.3% in group 1 (p = 0.033). Radiographic analysis documented a difference in terms of stress shielding and thinning of medial and lateral cortex in favour of group 1. Moreover, patients of group 1 showed a higher varus angle at six month follow-up.

CONCLUSION

In patients with high cortical index, a short stem shows better clinical and radiological outcomes at five year follow-up.

Does Proximally Coated Single-Wedge Cementless Stem Work Well in Dorr Type C Femurs? Minimum 10-year Followup

BACKGROUND

Total hip arthroplasty (THA) with a proximally coated single-wedge (PSW) cementless stem had been generally considered not to be suitable for Dorr Type C femurs. This study compares the long term outcomes of PSW stem according to the type of proximal femoral geometry.

MATERIALS AND METHODS

307 primary THAs in 247 patients were performed with PSW cementless stem and followed up for over 10 years in this retrospective study. According to Dorr's criteria, 89 femurs were classified as Type A, 156 as Type B, and 62 as Type C. They were followed up for an average of 13.2 years (range 10.0-17.3 years). All the hips were evaluated clinically and radiologically.

RESULTS

There was no significant difference in stem survivorship and clinical outcomes including the incidence of thigh pain and the mean postoperative Harris hip score (HHS) in all three groups. No significant differences were observed in osteolysis, pedestal formation, or cortical hypertrophy among the groups. Radiolucent lines <2 mm in thickness in Gruen zone 4 and 7 (P = 0.003 and P = 0.044, respectively), spot-weld (P < 0.001), and stress shielding (P = 0.010) of proximal femur were more pronounced in Dorr C type femora than in Type A or B. Fifty-six intraoperative fractures were identified among 307 hips with PSW stems. The incidence of intraoperative or postoperative femoral fractures was not significantly different among the groups.

CONCLUSIONS

From over a 10-year followup, the PSW stem provided a recommendable option with satisfactory outcomes and excellent stem survivorship regardless of the Dorr type.

The effect of flexion alignment in total hip arthroplasty with a cementless tapered-wedge femoral stem

INTRODUCTION

The influence of stem sagittal alignment on clinical outcomes is unclear in total hip arthroplasty (THA). The purpose of this study is to assess the relationship between stem sagittal alignment and clinical and radiographic outcomes using 3D-CT.

MATERIALS AND METHODS

We performed 370 consecutive primary THAs between 2009 and 2013. After exclusion, 102 hips in 89 patients using single tapered-wedge stem were included. Mean follow-up was 4.7 years. Stem sagittal alignment was measured using CT, and patients were divided into flexion and neutral alignment groups. Clinical and radiographic outcomes were compared between two groups. Furthermore, we evaluated the anterior femoral offset and initial contact state.

RESULTS

There were no significant differences in clinical or radiographic outcomes between two groups. CT data analysis and multiple regression analysis showed flexion alignment increased anterior femoral offset (AFO) and Gruen zone 4 contact area.

CONCLUSIONS

There was no significant difference in clinical or radiographic outcomes between flexion and neutral alignment of the tapered-wedge stem at an average of 4.7 years of follow-up. The increase of AFO and distal contact area in flexion alignment could affect the improvement of impingement-free range of flexion and intraoperative fracture.

Short stem total hip arthroplasty: Potential explanations for persistent post-surgical thigh pain

Short stem uncemented femoral implants were developed with the aim of preserving proximal bone stock for future revisions, improving biomechanical reconstruction, aiding insertion through smaller incisions and potentially decreasing or limiting the incidence of thigh pain. Despite all the advantages of short stem designs, it remains unclear whether they are able to limit post-surgical thigh pain. In patients with short stem hip arthroplasty and persistent thigh pain, it is of the utmost importance to understand the potential etiologies of this chronic pain for selecting the appropriate treatment strategy. Therefore, this manuscript explores the hypothetical etiologies of persistent thigh pain in short stem total hip arthroplasty, including both peripheral factors (structural or biomechanical causes) and central factors (involvement of the central nervous system). First, intrinsic causes (e.g. aseptic femoral loosening and prosthetic joint infection) and extrinsic sources (e.g. muscle pathology or spinal pathology) of persistent thigh pain related to hip arthroplasty are explained. In addition, other specific peripheral causes for thigh pain related to the short stem prosthetic reconstruction (e.g. stem malalignment and micro-motion) are unraveled. Second, the etiology of persistent thigh pain after short stem hip arthroplasty is interpreted in a broader concept than the biomechanical approach where peripheral structural injury is believed to be the sole driver of persistent thigh pain. Over the past decades evidence has emerged of the involvement of sensitization of central nervous system nociceptive pathways (i.e. central sensitization) in several chronic pain disorders. In this manuscript it is explained that there might be a relevant role for altered central nociceptive processing in patients with persistent pain after joint arthroplasty or revision surgery. Recognition of a potential role for centrally-mediated changes in pain processing in total hip replacement surgery has important implications for treatment. Comprehensive treatment addressing peripheral factors as well as neurophysiological changes occurring in the nervous system may help to improve outcomes in patients with short stem hip arthroplasty and chronic thigh pain. Working within a biopsychosocial approach in orthopaedic surgery, specifically in relation to total hip arthroplasty, could be very important and may lead to more satisfaction. Further research is warranted.

Is the Direct Superior, Iliotibial Band-Sparing Approach Associated With Decreased Pain After Total Hip Arthroplasty?

BACKGROUND

Recently, the direct superior approach (DSA) has been introduced in total hip arthroplasty (THA) with the goal of limiting soft tissue dissection. This study's purpose was to use a visual pain diagram questionnaire to determine the location and severity of pain in patients undergoing THA via a DSA vs miniposterior approach (MPA).

METHODS

This was a prospective, Institutional Review Board (IRB)-approved investigation from 3 centers. Patients aged 18-70 years with a diagnosis of osteoarthritis were included. Two centers used the MPA, while 1 center the DSA. The DSA uses a 9- to 12-cm incision with its distal extent at the posterosuperior greater trochanter. Dissection into the iliotibial band is avoided, and the capsule at the inferior femoral neck is preserved. All THAs in both cohorts received a cementless, titanium, proximally coated femoral stem and a hemispherical acetabular component.

RESULTS

A total of 42 DSA and 196 MPA THA patients were included. Overall, 43% of patients reported pain in at least 1 of the 8 anatomic areas assessed. There was no difference in the incidence of moderate to severe pain in any anatomic area of interest between the MPA and DSA cohorts (P = .1-.9). Specifically, the incidence of moderate to severe trochanter (17% MPA vs 17% DSA, P = .9), anterior thigh (15% MPA vs 17% DSA, P = .9), and lateral thigh pain (12% MPA vs 12% DSA, P = .9) was nearly identical in both cohorts.

CONCLUSION

This study was unable to demonstrate a difference in the incidence of residual pain after use of a DSA or an MPA approach after THA.

Proximal Femur Bone Density Decreases up to 5 Years After Total Hip Arthroplasty in Young, Active Patients

BACKGROUND

The number of young, active patients undergoing hip arthroplasty continues to increase. The purpose of this study was to evaluate femoral bone density over a 5-year period after hip arthroplasty in young, active patients.

METHODS

A total of 96 patients (103 hips) with a presymptomatic University of California at Los Angeles (UCLA) score ≥6 who had a total hip arthroplasty (THA; 45 hips) or surface replacement arthroplasty (SRA; 58 hips) were prospectively enrolled. UCLA and Harris Hip Scores were collected preoperatively and postoperatively, and dual energy X-ray absorptiometry scans were performed at 6 weeks, 6 months, 1 year, 2 years, and 5 years postoperatively. Bone density was analyzed for 7 traditional Gruen zones in both groups and 6 femoral neck zones in the SRA group. Bone density ratios were calculated for change in bone density compared with baseline.

RESULTS

No differences were present in the preoperative or postoperative UCLA or Harris Hip Scores between the SRA and THA cohorts (P = .07-.7). In the THA group, bone density never returned to baseline during the 5-year period in Gruen zones 1 (91.2% of baseline), 2 (94.8%), 6 (97.3%), and 7 (89.2%). There were no decreases in bone mineral density ratio for the femoral Gruen zones in the SRA group at any interval. Femoral neck bone density after SRA increased on the lateral, tension side up to 5 years postoperatively (P < .0001).

CONCLUSION

Young, active patients undergoing THA with cementless femoral fixation demonstrate reductions in bone density in the proximal femur in Gruen zones 1, 2, and 7 over time.

Residual Symptoms and Function in Young, Active Hip Arthroplasty Patients: Comparable to Normative Controls?

BACKGROUND

Whether patient-reported symptoms and function after total hip and surface replacement arthroplasty in young, active patients compare favorably to those without known hip pathology has not been investigated.

METHODS

A retrospective, multicenter study was designed in which 5 centers contributed patients aged <60 years with a presymptomatic University of California at Los Angeles score ≥6 undergoing hip arthroplasty. Data were collected by an independent, third-party survey center that administered a questionnaire assessing patient satisfaction and function. A "control" population with no prior hip interventions or hip pathology limiting their activity, that met the age and activity criteria, was identified for comparison using multivariate regression analyses.

RESULTS

Eight-hundred six hip arthroplasties (682 total hip arthroplasty, 124 surface replacement arthroplasty) and 158 controls were included. A greater percentage of hip arthroplasty patients were male and aged >50 years which was controlled during multivariate regression analyses. Control patients reported the presence of a limp (15%), stiffness (11%), and pain in the hip (8%), but to a lesser degree than hip arthroplasty patients. Control patients were less likely to report pain in the hip (odds ratio [OR] = 0.4, 95% confidence interval [CI] = 0.2-0.7, P = .006), stiffness in the hip (OR = 0.5, 95% CI = 0.3-0.8, P = .02), and a limp (OR = 0.5, 95% CI = 0.3-0.8, P < .001) vs patients undergoing hip arthroplasty.

CONCLUSION

When interviewed by an independent third party, a substantial portion of control patients did note the presence of hip symptoms, but to a lesser degree than young, active patients undergoing hip arthroplasty.

Frequency, Developing Time, Intensity, Duration, and Functional Score of Thigh Pain After Cementless Total Hip Arthroplasty

BACKGROUND

Although thigh pain is an annoying problem after total hip arthroplasty (THA), little information has been known about its natural course.

METHODS

To determine the frequency, time of onset, and duration of thigh pain after cementless THA, we evaluated 240 patients (240 hips) who underwent primary THA because of femoral head osteonecrosis with the use of a single tapered stem.

RESULTS

Twenty-seven patients (11.3%) experienced thigh pain during the follow-up of 3-11 years (mean, 84 months). The pain developed 2-78 months (median, 25 months) after THA. The 75% of pain developed within 36 months. In 25 patients, the pain disappeared postoperatively 1 month-64 months (mean, 17.4 months), and 2 patients (7.4%, 2/27) had persistent thigh pain. There were no differences in the latest Harris Hip Score between the thigh pain group and no thigh pain group.

CONCLUSION

Our results provided basic information about the natural history of thigh pain after cementless THA with a tapered stem design.

Radiographic alterations in short-stem total hip arthroplasty: a 2-year follow-up study of 216 cases

INTRODUCTION

In recent years a variety of short-stems have been introduced. Stable osteointegration is a key factor for a satisfactory long-term result. The purpose of this study was to evaluate postoperative radiological alterations and subsidence, as a result of using a newly developed device, over a 2-year follow-up.

METHODS

216 short-stems were implanted in combination with a cementless cup. Patients were allowed full weight-bearing on the first day postoperatively. Pre- and postoperative x-rays were done using a standardised technique. Radiological alterations, such as bone resorption, radiolucency, osteolysis and cortical hypertrophy were detected and located using modified Gruen zones, and subsidence was measured via a conventional digital technique over a 2-year follow-up. In addition, Harris Hip Score (HHS), rest pain and load pain on the visual analogue scale (VAS) were assessed respectively.

RESULTS

At 2-year follow-up 6 stems (2.9%) showed nonprogressive radiolucent lines with a maximum width of 2 mm. Resorption of femoral bone stock was detected in a total of 8 cases (3.9%). Femoral cortical hypertrophy was seen in a total of 9 hips (4.4%). No patient showed osteolysis. A measureable subsidence of at least 2 mm was observed in a total of 15.7% (32 cases) after 6 weeks, corresponding to an initial settlement given full weight-bearing ambulation. Only 1.1% (2 cases) showed further progression at the 6-month follow-up, whereas at the 1- and 2-year follow-ups no further subsidence was observed. After 2 years HHS was 98.1 (65.0-100.0), rest pain on the VAS was 0.2 (0.0-7.0) while load pain was 0.4 (0.0-7.0).

CONCLUSIONS

The results of this radiographic analysis give support to the principle of using metaphyseal anchoring, calcar guided short-stems. The low incidence of bony alterations after a follow-up of 2 years indicates a physiological load distribution. After mild initial subsidence a stable osteointegration can be achieved over time.

A comparison of a short versus a conventional femoral cementless stem in total hip arthroplasty in patients 70 years and older

BACKGROUND

The aim of this study was to compare clinical and radiological outcomes between a short femoral cementless stem and a conventional femoral cementless stem in total hip arthroplasty in patients 70 years and older.

METHODS

From December 2011 and July 2013, we retrospectively reviewed 50 patients (55 hips) 70 years and older treated with a short femoral cementless stem and 53 patients (58 hips) 70 years and older treated with a conventional femoral cementless stem. Their mean age was 74 ± 13.2 years and 75 ± 10.4 years, respectively. The mean follow-up was 40 ± 3.6 months and 42 ± 5.2 month, respectively. They were pre- and postoperatively evaluated by the clinical and radiological examination.

RESULTS

There was no difference in terms of average operative time, average estimated blood loss, and average hemoglobin at discharge between the short stem and the conventional stem. No patients with the short stem had intra-operative fracture, but five patients with the conventional stem had intra-operative fracture. At final follow-up, there was no statistically significant difference in Harris Hip Score, and radiographic review level between two stems. No hip with the short stem had thigh pain, but six hips with the conventional stem had thigh pain at the final follow-up. No component was revised for aseptic loosening in either group.

CONCLUSIONS

Our study demonstrated that both short cementless stem and conventional cementless stem provided stable fixation and achieved a satisfactory result in patients 70 years and older and the short cementless stem had a low incidence of thigh pain and intra-operative fracture.

Incidence and Location of Pain in Young, Active Patients Following Hip Arthroplasty

Persistent pain following hip arthroplasty remains a concern, especially in young, active patients. Four hundred twenty patients less than 60 years of age with a pre-symptomatic UCLA score ≥ 6 (196 total hip arthroplasty [THA]; 224 surface replacement arthroplasty [SRA]) completed a pain-drawing questionnaire investigating the location, severity, and frequency of pain around the hip. At a mean of 2.9 years of follow-up, 40% reported pain in at least one location around the hip. There was no difference in the incidence of groin pain between SRA and THA patients (32% vs. 29%, P=0.6), but THA patients had a greater incidence of anterior (25% vs. 8%, P<0.001) and lateral (20% vs. 10%, P=0.01) thigh pain. A high percentage of young, active patients experience persistent pain following hip arthroplasty.

Revision total hip arthroplasty using cemented collarless double-taper femoral components at a mean follow-up of 13 years (8 to 20): an update

The outcome of 219 revision total hip arthroplasties (THAs) in 98 male and 121 female patients, using 137 long length and 82 standard length cemented collarless double-taper femoral stems in 211 patients, with a mean age of 72 years (30 to 90) and mean follow-up of six years (two to 18) have been described previously. We have extended the follow-up to a mean of 13 years (8 to 20) in this cohort of patients in which the pre-operative bone deficiency Paprosky grading was IIIA or worse in 79% and 73% of femurs with long and standard stems, respectively. For the long stem revision group, survival to re-revision for aseptic loosening at 14 years was 97% (95% confidence interval (CI) 91 to 100) and in patients aged > 70 years, survival was 100%. Two patients (two revisions) were lost to follow-up and 86 patients with 88 revisions had died. Worst-case analysis for survival to re-revision for aseptic loosening at 14 years was 95% (95% CI 89 to 100) and 99% (95% CI 96 to 100) for patients aged > 70 years. One additional long stem was classified as loose radiographically but not revised. For the standard stem revision group, survival to re-revision for aseptic loosening at 14 years was 91% (95% CI 83 to 99). No patients were lost to follow-up and 49 patients with 51 hips had died. No additional stems were classified as loose radiographically. Femoral revision using a cemented collarless double-taper stem, particularly with a long length stem, and in patients aged > 70 years, continues to yield excellent results up to 20 years post-operatively, including in hips with considerable femoral metaphyseal bone loss.

Radiographic parameters associated with pain following total hip and surface arthroplasty

Pain following total hip arthroplasty (THA) and surface arthroplasty (SRA) remains a significant source of patient dissatisfaction. Two hundred twenty-four SRA and 196 THA patients completed a pain drawing questionnaire and postoperative radiographic measurements of component positioning were performed. In the SRA cohort, 11 of 21 patients (52%) with acetabular uncoverage of ≥5 mm versus 43 of 147 (29%) with acetabular uncoverage of ≤4.9 mm reported groin pain (P=.03). In the THA cohort, an increased distal-third canal fill ratio and a lower canal calcar ratio trended towards a higher incidence of thigh pain (P=.10 and .06), while a decreased mid-third canal fill ratio was associated with increased severity of thigh pain (P=.04). This study identifies associations between radiographic findings and pain following THA and SRA.

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.

Correlation between stress shielding and clinical outcomes after total hip arthroplasty with extensively porous coated stems

Relations between stress shielding and the clinical outcomes of total hip arthroplasty(THA) remain topics of debate. This study was performed on 51 patients that underwent unilateral primary THA with an extensively porous coated stem. Contralateral normal femurs were used as controls. Dual energy x-ray absorptiometry data was used to quantify bone mineral density(BMD) on proximal femurs. Clinical outcomes were estimated by using Harris hip scores (HHSs). BMD in operated sides were lower than in control sides. HHS and pain scores were not related to BMD changes. An extensively porous coated stem can be used for THA and that concerns regarding the effects of stress shielding of the proximal femur are unwarranted.

Groin pain after replacement of the hip

Persistent groin pain after seemingly successful total hip replacement (THR) appears to have become more common. Recent studies have indicated a high incidence after metal-on-polyethylene and metal-on-metal conventional THR and it has been documented in up to 18% of patients after metal-on-metal resurfacing. There are many causes, including acetabular loosening, stress fracture, and iliopsoas tendonitis and impingement. The evaluation of this problem requires a careful history and examination, plain radiographs and an algorithmic approach to special diagnostic imaging and tests. Non-operative treatment is not usually successful. Specific operative treatment depending on the cause of the pain usually involves revision of the acetabular component, iliopsoas tenotomy or other procedures, and is usually successful. Here, an appropriate algorithm is described.

Residual groin pain at a minimum of two years after metal-on-metal THA with a twenty-eight-millimeter femoral head, THA with a large-diameter femoral head, and hip resurfacing

BACKGROUND

Groin pain may persist in up to 4.3% of patients after total hip arthroplasty and up to 18% of patients one year after hip resurfacing. The incidence of this problem after total hip arthroplasty with a large-diameter femoral head is unknown.

METHODS

We analyzed the natural history of groin pain and its clinical consequences during the first two years after three types of hip arthroplasty. Data were collected prospectively on 279 patients. Eighty-five patients had a polyethylene sandwich metal-on-metal total hip arthroplasty with a 28-mm-diameter femoral head, 105 had hip resurfacing, and eighty-nine had a total hip arthroplasty with a large-diameter femoral head component with three other cup designs (forty-nine in this group had the same monoblock acetabular cup design as those who had hip resurfacing).

RESULTS

At the twenty-four-month follow-up evaluation, seventy-seven patients (28%) reported at least one painful area around the hip and thirty-four patients (12.2%) had pain at more than one location. At three months, the incidence of groin discomfort was significantly increased in those who had hip resurfacing (30.5%) and in those who had total hip arthroplasty with a large-diameter femoral head (30%) compared with those who had total hip arthroplasty with a 28-mm femoral head (18.3%). This incidence decreased at two years (14.9%, 16.9%, and 12.9%, respectively). At twenty-four months postoperatively, eleven (four who had hip resurfacing, six who had total hip arthroplasty with the large-diameter head, and one who had total hip arthroplasty with the 28-mm head) of forty-one patients who had groin pain had not reported groin pain at previous follow-up evaluations. Of the forty-one patients reporting groin pain at the time of the last follow-up, twenty-three patients (56%) did not seek further evaluation or treatment, nine had revision surgery (22%), and the remaining nine patients thought the pain was substantial enough to warrant further evaluation and treatment.

CONCLUSIONS

When the exact source of groin pain cannot be found after total hip arthroplasty, careful follow-up should be done as local reactions to metal-on-metal implants and component loosening may take time to become apparent clinically or on imaging studies.

The Frank Stinchfield Award: the impact of socioeconomic factors on outcome after THA: a prospective, randomized study

BACKGROUND

Most studies of total hip arthroplasty (THA) focus on the effect of the type of implant on the clinical result. Relatively little data are available on the impact of the patient's preoperative status and socioeconomic factors on the clinical results following THA.

QUESTIONS/PURPOSES

We determined the relative importance of patient preoperative and socioeconomic status compared to implant and technique factors in predicting patient outcome as reflected by scores on commonly utilized rating scales (eg, Harris Hip Score, WOMAC, SF-12, degree of patient satisfaction, or presence or severity of thigh pain) following cementless THA.

METHODS

All patients during the study period were offered enrollment in a prospective, randomized study to receive either a titanium, tapered, proximally coated stem; or a Co-Cr, cylindrical, extensively coated stem; 102 patients were enrolled. We collected detailed patient data preoperatively including diagnosis, age, gender, insurance status, medical comorbidities, tobacco and alcohol use, household income, educational level, and history of treatment for lumbar spine pathology. Clinical evaluation included Harris Hip Score, SF-12, WOMAC, pain drawing, and UCLA activity rating and satisfaction questionnaire. Implant factors included stem type, stem size, fit in the canal, and stem-bone stiffness ratios. Minimum 2 year followup was obtained in 95% of the enrolled patients (102 patients).

RESULTS

Patient demographics and preoperative status were more important than implant factors in predicting the presence of thigh pain, dissatisfaction, and a low hip score. The most predictive factors were ethnicity, educational level, poverty level, income, and a low preoperative WOMAC score or preoperative SF-12 mental component score. No implant parameter correlated with outcome or satisfaction.

CONCLUSION

Socioeconomic factors and preoperative status have more impact on the clinical outcome of cementless THA than implant related factors.

LEVEL OF EVIDENCE

Level I, prospective, randomized clinical trial. See the guidelines online for a complete description of level of evidence.

Patients' experience of pain and pain relief following hip replacement surgery

AIMS

The aim of this study was to describe patients' experience of pain and pain relief following hip replacement surgery.

BACKGROUND

Annually, many patients undergo hip replacement surgery. Previous research has focused largely on the long-term effects on pain for patients who undergo hip replacement surgery and to a lesser degree on their subjective, early postoperative pain experience.

DESIGN

A descriptive qualitative design was used.

METHODS

The study was carried out in an orthopaedic ward at a hospital in Sweden during 2006. Qualitative interviews were conducted with 15 patients who had undergone hip replacement surgery. Data were analysed by means of qualitative content analysis.

RESULTS

The postoperative pain experience was characterised in terms of interrelated contexts of time, various bodily activities and postoperative pain intensity. The postoperative pain intensity was characterised in terms of intensive and worst imaginable, strange feelings and fear and a feeling of faintness. Easing of postoperative pain was related to professional care features, such as nursing staff, pharmacological pain relief and technical aids. Self-care features were related to relieving body positions, endurance and looking ahead.

CONCLUSION

Although the development of total hip replacement surgery has been very successful, there are issues that need to be addressed in relation to postoperative pain management. The findings in this study show that there are reasons for making a more concerted effort to develop postoperative pain management, particularly during the first few days after surgery.

RELEVANCE TO CLINICAL PRACTICE

The results provide some indication that pain management for this group of patients in the early postoperative period needs to be improved to reduce the fear of moving and improve the process of regaining independence. Devoting more attention to the patients during the initial postoperative phase may be the key to improve the training and making it even more effective.

Tibia pain at end of stem with stemmed revision total knee arthroplasty: treatment with cortical strut graft technique

End-of-stem pain related to stemmed revision total knee arthroplasty has been described in the literature as being caused by the elastic modulus mismatch from the stem tip and the native bone. This phenomenon has also been described after total hip arthroplasty, which can be successfully treated by placement of a cabled cortical strut graft at the tip of the femoral stem. Currently, the treatment option for this tibial-sided end-of-stem pain is a re-revision total knee arthroplasty in attempts of alleviating the modulus mismatch. This case report is the first to describe a cabled cortical strut graft technique for the tibial end-of-stem pain associated with stemmed revision total knee arthroplasty.

Proximally versus fully porous-coated femoral stems: a multicenter randomized trial

There are two broad-based categories of cementless femoral component designs: proximally porous-coated and fully porous-coated. While both have been widely used, there remains debate regarding differences in clinical outcome scores, relative incidence of thigh pain, and development of stress shielding. We investigated these variables in a multicenter prospective randomized blinded clinical trial of 388 patients from three centers: 198 patients had a proximally porous-coated tapered cementless femoral component and 190 patients had a fully porous-coated cementless femoral component. A minimum followup of 2 years (mean, 6.7 years; range, 2.0-8.65 years) was available in 367 of the 388 patients (95%). We observed no differences in age at surgery, body mass index, or preoperative clinical outcome scores (WOMAC, SF-12, Harris hip score, UCLA activity, thigh pain) with the two groups. We determined serial bone density changes in a subcohort of 72 patients from two of the three centers. The postoperative clinical outcome scores were similar at all followup intervals, and we observed no differences in the incidence of thigh pain at any time. Bone density reduction in Gruen Zone 7 was greater with the fully coated stem than the proximally coated stem (24% versus 15% reduction, respectively). Both fully and proximally coated stems performed well, with no clinical differences at 2 years' followup, except in bone mineral density evaluations.

LEVEL OF EVIDENCE

Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Prospective, randomized comparison of cobalt-chrome and titanium trilock femoral stems

The purpose of this article was to demonstrate the efficacy of a cementless, flat, tapered wedge femoral stem and compare cobalt-chrome and titanium femoral stems with this design. Three hundred ninety femoral stems observed for a mean of 4.7 years (2.0-8.9 years) were prospectively evaluated with clinical and radiographic follow-up. Hips were stratified by Dorr classification, bone stock (femoral index), size of implant used, and material of femoral implant. Survivorship of the femoral stem at 8.9 years was 99.8% with no significant difference between cohorts. Thigh pain (4.9%) was more common with cobalt-chrome femoral stems (6.5%) than titanium femoral stems (3.1%). The flat, tapered wedge femoral stem design provides excellent femoral reconstruction in total hip arthroplasty. On the basis of this study, we use titanium femoral stems.

Prevalence and functional impact of patient-perceived leg length discrepancy after hip replacement

The aim of this postal survey was to determine the prevalence and impact of patient-perceived leg length discrepancy (LLD) at 5-8 years after primary total hip replacement (THR). A postal audit survey was undertaken of all consecutive patients who had a primary unilateral THR at one elective orthopaedic centre between April 1993 and April 1996. The questionnaire included the Oxford hip score (OHS) and questions about LLD. Questionnaires were received from 1,114 patients. In total, 329 THR patients (30%) reported an LLD, although radiographic analysis revealed that only 36% of these patients had anatomical LLD. Patients with a perceived LLD had a significantly poorer OHS (p < 0.001) and reported more limping than those patients without a perceived LLD. This study found that a third of patients perceived an LLD after THR and that perceived LLD was associated with a significantly poorer midterm functional outcome.