The effect of acetabular and femoral component version on dislocation in primary total hip arthroplasty

Purpose

The purpose of the present study was to: (1) investigate the variation of both acetabular and femoral component version in a large series of consecutive primary THA patients, and (2) to better define the associations of acetabular and femoral component alignment and clinical factors with subsequent hip dislocation in those patients.

Methods

We analyzed CT scans of 1,555 consecutive primary THAs and measured version of the components. We also documented the frequency and direction of subsequent dislocation as well as femoral head size, posterior tissue repair, any history of previous hip surgery, and gender.

Results

The dislocation rate after THA was 3.22 %. The dislocation risk was 1.9 times higher if cup anteversion was not between 10° and 30°. Compared to hips that did not dislocate, those that experienced anterior dislocation had a significantly greater combined anteversion; those that dislocated posteriorly had a significantly smaller combined anteversion. Hips with previous rotational acetabular osteotomy or head size smaller than 28 mm correlated with an increased dislocation rate.

Conclusion

The dislocation risk could be higher if cup anteversion was not between 10° and 30°. Greater combined anteversion could be a risk factor of anterior dislocation, and posterior dislocation could be more common in smaller combined anteversion.

     

Dislocation and its recurrence after revision total hip arthroplasty

Purpose

Dislocation is a leading cause of failure after revision total hip arthroplasty (THA). This study was conducted to examine the risk factors for dislocation as well as their recurrence after revision THA.

Methods

We retrospectively reviewed 178 revision THAs in 162 patients between 1998 and 2013. The mean patient age was 65.2 years at operation and the mean follow-up period was 6.7 years. Multivariate logistic regression was performed to identify risk factors for dislocation, and further comparison was made between patients with single and recurrent dislocations.

Results

Sixteen hips in 15 patients (9.0 %) dislocated at a mean of 9.1 months (range, 0–83 months) after revision THA. Multivariate analysis identified advanced age (odds ratio [OR]?=?2.94/10 years) and osteonecrosis of the femoral head (OR?=?7.71) as the independent risk factors for any dislocations. Risk factors for recurrent dislocations, which were observed in eight hips (50 %), were later dislocations (≥4 months) and lower BMI.

Conclusion

Dislocation is a serious problem after revision THA with multiple risk factors. Although our findings were limited to revision THAs done through posterolateral approach, recognition of these factors is helpful in patient education and surgical planning.

     

Subtrochanteric femoral shortening osteotomy combined with cementless total hip replacement for Crowe type IV developmental dysplasia: a retrospective study

Background

Total hip replacement for high dislocation of the hip presents some difficulties, considering patients’ young ages, the abnormal hip anatomy and the high rate of complications. In this study, we present our experience in terms of clinical and radiological results in the treatment of Crowe type IV hips with subtrochanteric femoral shortening osteotomy and cementless total hip replacement.

Materials and Methods

We retrospectively reviewed 15 patients with Crowe type IV hip dysplasia (two bilateral cases for a total of 17 hips) treated with cementless total hip replacement associated with shortening subtrochanteric osteotomies (nine transversal and eight Z-shape osteotomies) between March 2000 to February 2006. The mean follow-up was 88 months (range 63–133). Harris hip score, leg length discrepancy, neurological status, union status of the osteotomy and the component stability were the criteria of the evaluation. All complications were noted.

Results

The mean HHS improved from 38.3 (range 32–52) to 85.6 (range 69–90). The mean preoperative leg length discrepancy was of 45 mm (range 38–70) and reduced to a mean of 12 mm (range 9–1.6) postoperatively. All osteotomies resulted healed at an average of 12.3 weeks (range 10–15). No cases of delayed union or nonunion were detected. Two patients (11%) showed early symptoms of sciatic nerve palsy which resolved uneventfully in 6 months. There was no migrations and none of the implants required revision.

Conclusions

Cementless THA with shortening subtrochanteric osteotomy is an effective method in the treatment of patients with Crowe type IV development dysplasia of the hip.

Level of evidence

IV.

     

A balanced approach for stable hips in children with cerebral palsy: a combination of moderate VDRO and pelvic osteotomy

Background

Hip reconstructive surgery in cerebral palsy (CP) patients necessitates either femoral varus derotational osteotomy (VDRO) or pelvic osteotomy, or both. The purpose of this study is to review the results of a moderate varisation [planned neck shaft angle (NSA) of 130°] in combination with pelvic osteotomy for a consecutive series of patients.

Methods

Patients with CP who had been treated at our institution for hip dysplasia, subluxation or dislocation with VDRO in combination with pelvic osteotomy between 2005 and 2010 were reviewed.

Results

Forty patients with a mean follow-up of 5.4 years were included. The mean age at the time of operation was 8.9 years. The majority were non-ambulant children [GMFCS I–III: n = 11 (27.5 %); GMFCS IV–V: n = 29 (72.5 %)]. In total, 57 hips were treated with both femoral and pelvic osteotomy. The mean pre-operative NSA angle of 152.3° was reduced to 132.6° post-operatively. Additional adductor tenotomy was performed in nine hips (16 %) at initial operation. Reimers’ migration percentage (MP) was improved from 63.6 % pre-operatively to 2.7 % post-operatively and showed a mean of 9.7 % at the final review. The results were good in 96.5 % (n = 55) with centred, stable hips (MP <33 %), fair in one with a subluxated hip (MP 42 %) and poor in one requiring revision pelvic osteotomy for ventral instability.

Conclusions

This approach maintains good hip abduction and reduces soft-tissue surgery. Moderate varisation in VDRO in combination with pelvic osteotomy leads to good mid-term results with stable, pain-free hips, even in patients with severe spastic quadriplegia.

     

Acute revision hip arthroplasty: a previously unrecognized risk factor for heterotopic ossification

Background

The aim of this retrospective review was to determine the incidence and severity of heterotrophic ossification (HO) following acute revision total hip arthroplasty (THA), and whether this represents a significant risk factor for HO that should be treated prophylactically.

Materials and methods

A total of seven patients (three men and four women) with a mean age of 55 years (39–70 years) who underwent a reoperation of their THA for any reason that required a hip arthrotomy within 3 weeks of their primary or revision THA were included, with a mean follow-up of 8.8 years (2–12 years). All patients were evaluated radiographically for any evidence of HO and clinically using the Harris Hip Score.

Results

All seven hips (100 %) developed HO, with 71 % being severe (Brooker III and IV HO). One hip (14 %) developed Brooker IV HO, four hips (57 %) developed Brooker III HO, and two hips (29 %) developed Brooker II HO. The patient’s range of motion varied, but was very limited in three patients. Three patients (42.8 %) were not satisfied with their surgery; one patient had Brooker IV HO, and two patients had Brooker III HO.

Conclusion

Acute reoperation after primary or revision THA is a significant risk factor for the development of extensive HO, which requires prophylactic treatment.

     

Lateral femoral cutaneous nerve injury with the direct anterior approach for total hip arthroplasty

Purpose

Although injury of the lateral femoral cutaneous nerve (LFCN) is a known complication after total hip arthroplasty (THA) via the direct anterior approach (DAA), the impact of this complication on postoperative quality of life (QOL) is unclear. This study aims to investigate the incidence of LFCN injury after DAA for THA, and to determine the impact of LFCN injury on QOL and hip function.

Methods

We prospectively investigated 122 hips operated upon using the DAA regarding the incidence of LFCN injury using self-reported questionnaires, hip functional scores such as the Harris Hip Score (HHS) and the Japanese Orthopaedic Association (JOA) score, and patient-reported outcomes such as the Western Ontario and McMaster Universities Osteoarthritis Index, the Japanese Orthopaedic Association Hip disease Evaluation Questionnaire (JHEQ), and the Forgotten Joint Score-12 (FJS).

Results

LFCN injury was seen in 39 hips (31.9 %). In affected hips, the leading symptom was hypo-aesthesia (46.2 %), followed by tingling or jolt-like sensation (28.2 %). There was no difference in the HHS and JOA score between those with LFCN injury and those without. There was a significant difference in the FJS-12 between the two groups (50.9?±?25.3 for hips with LFCN injury vs 64.3?±?25.7 without, p?=?0.01). There was a non-significant tendency for patients with LFCN injury to have a lower JHEQ than those without (63.6?±?19.6 for hips with LFCN injury vs 70.8?±?22.9 without, p?=?0.13).

Conclusions

The incidence of LFCN injury decreased QOL but not hip function after DAA for THA.

     

Long-term follow-up of primary total hip arthroplasty with the Alloclassic Variall system

Purpose

The aim of the present study was to evaluate the clinical and radiographic results of primary total hip arthroplasty (THA) performed with the Alloclassic Variall system (a modified version of the Alloclassic Zweymüller system) and to compare them with those in the literature for the original system.

Methods

Between January 2001 and December 2002, 273 consecutive primary THAs were performed in 259 patients at a single centre with the study system, using ceramic-on-ceramic (81.7 %) or ceramic-on-highly-crosslinked-polyethylene (18.3 %) articulations.

Results

At the time of this study, 28 patients (29 hips; 10.6 %) had died and 40 (43 hips; 15.8 %) were lost to follow-up. Seventeen patients (19 hips; 7.0 %) could be reached only by telephone. There were four revisions in four patients (1.5 %), all involving only the femoral component. Ten-year Kaplan-Meier survival with revision of any component for any reason as the endpoint was 98.4 % (95 % confidence interval: 96.9–100 %; 30 hips remained ‘at risk’). A total of 170 unrevised patients (178 hips; 65.2 %) were assessed clinically and radiographically at a median follow-up of 9.3 years (interquartile range [IQR] 8.8–9.8 years). The median Harris hip score (HHS) was 99.9 points (IQR 97.7–100). The score did not differ significantly between the two articulations. There was no sign of radiographic loosening.

Conclusions

The ten-year implant survival and the HHS score outcomes for THAs performed with the novel system were in line with those documented in the literature for its predecessor.

     

Greater trochanter chip fractures in the direct anterior approach for total hip arthroplasty

Background

The direct anterior approach (DAA) for the treatment of total hip arthroplasty (THA) has gained popularity in recent years. Chip fractures of the greater trochanter are frequently seen, but the risk factors for such fractures are unknown. The study aimed to identify the risk factors for chip fractures in patients undergoing primary THA by the DAA during the surgeons’ learning curve.

Materials and methods

From November 2011 to April 2015, the first experiences of three surgeons who performed 120 THAs by the DAA (120 hips; 40 cases per beginner surgeon) were included. The incidence of chip fracture of the greater trochanter, the size of the greater trochanter as measured by computed tomography, and the patients’ characteristics were retrospectively investigated.

Results

After exclusion of 11 hips, the remaining 109 hips were investigated. Chip fracture of the greater trochanter was identified in 32 hips (29.4 %). Univariate analysis with and without fractures showed that the width and depth of the greater trochanter were statistically significant risk factors (p = 0.02 and p < 0.001, respectively). Multivariate analysis using a logistic regression model demonstrated that the depth of the greater trochanter was an independent risk factor for chip fracture of the greater trochanter (OR 1.725; 95 % CI 1.367–2.177; p < 0.001).

Conclusion

The size of the greater trochanter was identified as a risk factor for chip fracture of the greater trochanter. Novice surgeons should pay attention to the size of the greater trochanter when performing THA by the DAA.

     

Influence of the contralateral hip state after total hip arthroplasty on patient-reported outcomes measured with the Forgotten Joint Score-12

Purpose

The purpose of this study was to examine the influence of the contralateral hip state on postoperative assessment using the Forgotten Joint Score-12 (FJS-12) in comparison with the McMaster Universities Osteoarthritis Index (WOMAC) and the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ).

Methods

One hundred and thirty-four hips underwent total hip arthroplasty (THA) between 2014 and 2015. Of these, the subjects were 106 hips with degenerative hip arthrosis as a primary disease for whom initial THA was performed on the affected side. The WOMAC and JHEQ were investigated before surgery and 1 month, 6 months, and 1 year after surgery. The FJS-12 was examined 1 month, 6 months, and 1 year after surgery.

Results

We divided the subjects into three groups based on the state of the contralateral hip, which was not surgically treated in this study: healthy (n = 43), THA (n = 31), and OA (n = 31) groups. One year after surgery, the mean FJS-12 scores in the healthy, THA, and OA groups were 69.1, 52.8, and 68.0 points, respectively. In the THA group, the score was significantly lower than in the healthy and OA group. There were no significant differences in WOMAC and JHEQ scores among the three groups.

Conclusions

The FJS-12 score in the presence of an arthroplasty on the contralateral side was more markedly influenced by the contralateral hip state compared with that in the presence of contralateral painful OA. This result suggests that it is necessary to understand the characteristics of PROs and utilize them for post-THA assessment.

     

Total hip arthroplasty using a Kerboull-type plate for rapidly destructive coxarthrosis: comparison with uncemented acetabular component

Introduction

Clinical outcomes of total hip arthroplasty (THA) to treat rapidly destructive coxarthrosis (RDC) have been reported, but to our knowledge, there have been no studies comparing implants. The aim of this study was to examine the effectiveness of acetabular reconstruction for RDC by comparing the clinical results of THA using a Kerboull-type plate with an uncemented cup.

Patients and methods

Among 921 primary THAs performed between 2006 and 2014, 27 were performed for the treatment for RDC using a Kerboull-type plate or a conventional uncemented cup. A Kerboull-type plate for acetabular reinforcement device was used in 13 hips and an uncemented cup in 14 hips. The mean follow-up period was 61.2 months.

Results

The duration of surgery was 156.8 ± 36.4 min in the Kerboull-type plate group and 103.3 ± 14.4 min in the uncemented cup group, being significantly longer in the former (P = 0.0002). In the Kerboull-type plate group and the uncemented cup group, the 5-year survival rates were 100 and 83.9 %, respectively. Recurrent dislocation was observed in two cases in which the posterior approach had been used.

Conclusions

In our study, the loosening of the acetabular components was noted in 14.3 % of uncemented cup-applied cases, but no loosening was noted in any Kerboull-type plate-applied case. Therefore, for RDC, in which objective evaluation of fragile bone quality is difficult, the use of the Kerboull-type plate, which disperses weight-bearing of the acetabular, may be an effective means to achieve early functional recovery as well as a long-term favorable outcome.

     

Hypertrophy of the tensor fascia lata muscle as a complication of total hip arthroplasty

Introduction

Hypertrophy of the tensor fascia lata muscle (HTFLM) is a rare complication after total hip arthroplasty (THA) and is a potential source of pain, palpable mass, or both.

Materials and methods

We retrospectively analyzed 1285 primary THAs and 482 THA revisions (THAR) performed at our center from 2008 to 2014. Among these, five patients had HTFLM (average age 68.8 years). The type of surgery and symptoms were evaluated, as were imaging studies (CT or MRI) of both hips (10 hips), and functional outcomes with the Merle d’Aubigné score.

Results

The suspected diagnosis was established at an average of 30.2 months after surgery. Four cases occurred after THA and one case after THAR. A modified Hardinge approach was used in four cases and a Röttinger approach in one case. Two cases had pain and palpable mass in the trochanteric region and three cases only pain. The asymmetric HTFLM of the THA side against the nonsurgical side was confirmed by measuring the cross section of the tensor fascia lata muscle on imaging. The sartorius muscle was measured for reference in each case. The Merle d’Aubigne scale had a mean value of 16.6 (range 13–18) at 38 months after the procedure.

Conclusions

HTFLM after THA is a benign condition that could be mistaken for a tumor when presenting as a palpable mass. We propose that it should be considered in the differential diagnosis of pain in the lateral aspect of hips that have previously undergone THA.

     

Cementless total hip arthroplasty in the treatment after acetabular fractures

Introduction

The outcomes of total hip arthroplasty (THA) for the treatment of posttraumatic arthritis after acetabular fractures were inferior to those after primary non-traumatic THA.

Methods

This study was performed in academic level I trauma center. From January 2011 to December 2014, a consecutive series of 21 patients (9 females), with average age of 56.7 years (range 29–75 years) who had posttraumatic hip joint arthritis after acetabular fractures, were included in our study. All patients underwent cementless THA. The average duration of follow-up was 26 months (range 24–36 months).

Results

At the latest follow-up, all patients could walk independently, thirteen (62%) patients had excellent Harris hip score, five (24%) had good HHS, and 3 (14%) had fair score. WOMAC scale decreased from 63 (range 42–92) to 4 (range 0–19). Two patients (9.5%) had heterotopic bone formation which did not affect the activity of the patients. There were no signs of loosening of the acetabular cups or around the femoral stem.

Conclusion

Cementless THA is an ideal treatment for posttraumatic hip arthritis with anatomic restoration of the hip center to improve the functional results and decrease the incidence of complications and revision rate.

     

Femoral shortening osteotomy in total hip arthroplasty for severe dysplasia: a comparison of two fixation techniques

Purpose

The purpose of this study was to compare two distinct fixation methods for a total hip replacement performed via transverse femoral shortening osteotomy for patients with severe hip dysplasia.

Methods

In this retrospective study we compared two fixation methods for total hip replacement of 78 hips in 76 patients exhibiting Crowe type IV developmental hip dysplasia (DDH). The hip replacements were performed via a transverse femoral shortening osteotomy and carried out between September 2009 and December 2013. Group I patients underwent fixation of the shortened femoral segment via a cable attached to the osteotomied segment, and group II patients underwent fixation with a plate and screw. We compared the two techniques based on operating time, osteotomy site union time, Harris hip score, hip loosening signs, and overall clinical outcomes.

Results

The mean operating time for groups I and II was determined to be 116.5?±?12.8 min and 137.7?±?14 min, respectively (p?<?0.05), while the average union time was 113?±?51 days for group I and 152?±?37 days for group II (p?<?0.05). Fixation of the femur with a cable (group I) is therefore faster and results in more rapid union time when compared to plate osteosynthesis at the osteotomy site (group II). We observed only one non-union in group I compared with three in group II (p?=?0.49). Harris hip scores at the final patient follow-up were 82.8?±?7.8 and 80.8?±?6.7 for groups I and II, respectively (p?=?0.23). Thus, notably no significant differences were observed between the groups with regard to clinical outcomes such as the Harris hip score or loosening of the replacement components.

Conclusion

Fixation of the removed femoral segment with a cable provided adequate rotational stability and decreased the operating time, leading to early union at the osteotomy site.

     

The effect of late radiotherapy on the progression of heterotopic ossification following total hip arthroplasty

Introduction

Heterotopic ossification (HO) is a known complication after total hip arthroplasty (THA). Radiotherapy is an effective prophylactic treatment for high-risk patients. However, there is no treatment for patients who did not receive prophylactic treatment and subsequently develop HO postoperatively. This study was to determine whether late radiotherapy treatment can prevent the progression of HO following THA.

Methods

A chart review was performed to identify patients who developed HO following THA and were treated with late radiotherapy. All these patients received radiotherapy after their 6- or 12-week postoperative follow-up. Patients were evaluated radiographically pre- and 2 years post-radiotherapy using ImageJ software to measure the difference in the area of HO that formed.

Results

Nine patients with a mean age of 64.5 years were identified. All patients developed HO within 6- or 12-week postsurgery and received later radiotherapy. Eight of the nine hips (89%) treated with late radiotherapy demonstrated no further progression in the amount of bone formed. Overall, there was an increase in the mean total area of HO by 19 mm² (2%), (p?=?0.12).

Conclusion

Late, low-dose radiotherapy is effective in preventing the progression of HO in patients who unexpectedly develop significant HO following THA.

     

Sartorius muscle-pedicle bone graft for osteonecrosis of the femoral head

Purpose

This study summarises the clinical efficacy of sartorius muscle-pedicle bone graft in osteonecrosis of the femoral head.

Methods

A total of 58 patients, including 53 men (61 hips) and five women (6 hips) with osteonecrosis of the femoral head, underwent sartorius muscle-pedicle bone grafting. Association Research Circulation Osseous (ARCO) staging was performed.

Results

The ARCO staging revealed 23 hips of stage I, 36 hips of stage II and eight hips of stage III. The average surgical duration was 65 minutes (range 45–90 minutes). A total of 55 (64 hips) of the 58 patients undergoing surgery were followed up, with a mean follow-up duration of 34.48 months (range, 24–48 months) and a median of 34 months. The outcome was excellent in 27, good in 24, normal in two, and poor in 11 hips, with a total good rating of 79.68 %. The Harris score of the hip joints in the last follow-up was significantly improved compared with pre-surgical scores (P?<?0.01). Imaging results showed that 21 hips were improved, 31 hips were stabilized and 12 hips were aggravated (of which 9 hips underwent total hip replacement). The survival rate of femoral head was 81.25 %.

Conclusion

Sartorius muscle-pedicle bone graft significantly promotes repair of osteonecrosis of the femoral head, improves the Harris score of the hip joints, with good clinical efficacy. It effectively improves the survival rate of femoral head, delaying or preventing artificial hip replacement.

     

Cementless total hip arthroplasty for patients with rheumatoid arthritis: a more than 10-year follow-up

Background/purpose

In this study, cementless THA was performed for RA patients, and its clinical outcomes, as well as radiographic findings and implant survival rates, were examined more than 10 years after surgery in comparison with the outcomes of the same procedure performed for patients with hip osteoarthritis (OA) during the same period.

Method

We studied 28 cases of THA for RA clinically and radiologically at a minimum follow-up duration of 10 years. The patients consisted of 4 males and 22 females, with a mean age at the time of surgery of 53.1. The clinical and radiographic results were compared with an age-matched and sex-matched group of patients who had undergone THA for the diagnosis of primary or secondary OA.

Results

In the RA group, the mean Harris hip score was 48.3 before surgery, and improved to 76.8 at the time of the final survey. In the control group, the score also improved from 46.8 before to 86.5 after surgery, while revealing significant differences between the groups (p = 0.0002). In the RA group, 2 joints required revision THA on the acetabular side due to aseptic loosening, while such revision was not performed on the femoral side despite the presence of more than 2 mm of subsidence in 2 joints. The implant survival rate was 92.9 and 100 % in the RA and control groups, respectively, without significant differences (p = 0.493).

Conclusions

Although its clinical outcomes were significantly different from those for OA, a satisfactory implant survival rate was achieved, at 92.9 % in RA patients.

     

Die perkutane Kalkaneusverschiebeosteotomie

Objectives

Correction of calcaneal malalignment as part of a hindfoot correction procedure.

Indications

Varus and valgus malalignment of the calcaneus, increased calcaneal pitch.

Contraindications

Osteoarthritis of the subtalar joint. Fixed and symptomatic deformities of the subtalar joint.

Surgical technique

After having identified and marked the desired planes of the osteotomy under image intensifier, a percutaneous v?shaped calcaneal osteotomy is performed. The osteotomy allows 3?dimensional correction of the calcaneus by defining the planes of the osteotomy. The procedure allows correction of varus and valgus deformities, as well as a change of the calcaneal pitch. The osteotomy is fixed by percutaneous screws.

Postoperative management

Postoperative care includes a 6-week period of partial weight bearing with 10 kg. The ankle joint should be mobilized. After x?ray control of sufficient bone healing, weight bearing can be increased stepwise over another 4?week period up to full body weight. A full length orthotic is recommended for at least 12 months with heel cup and good medial support.

Results

The procedure allows correction of calcaneal deformities with preservation of soft tissue, normally as part of a hindfoot correction, e.?g., in posterior tibial tendon insufficiency, varus deformities or total ankle replacement. In the literature and in our patients, the rate of injuries of the neurovascular bundle was not increased compared to open surgery. The average calcaneal shift was 1 cm, when necessary an additional correction was realized by rotation of the tuber calcanei.

     

Tantalum rod implantation for femoral head osteonecrosis: survivorship analysis and determination of prognostic factors for total hip arthroplasty

Purpose

The purpose of this study was to evaluate the moderate survival data of porous tantalum rod implants for the treatment of osteonecrosis of the femoral head (ONFH). Additionally, some independent prognostic factors for conversion to total hip arthroplasty (THA) were identified.

Methods

The porous tantalum rod population was obtained from a prospective, consecutive group of patients treated for Steinberg stage I and II osteonecrosis from April 2009 through July 2011. The historical core decompression and impaction of bone filling particle subjects underwent surgery from April 2007 through March 2009. Surgical data including time of surgery, blood loss, and cell transfusions were recorded. Post-operative values were measured for hospitalization length as well as days requiring a patient-controlled analgesia (PCA) pump. Primary outcomes were Harris hip score and survivorship analysis. Demographics and baseline characteristics included age, sex, etiology, bilateral disease, associated chronic systemic disease, Steinberg stage, Harris hip score, accompanied with bone marrow edema of femoral head, and osteonecrotic lesion size.

Results

Demographic/baseline characteristics were similar between two groups. At the post-operative follow-up of 62 months, Harris hip scores were significantly increased (P?<?0.0001) when compared to that before surgery in both groups. The magnitude of increase in the tantalum rod implant group was significantly greater than that in the control group (P?=?0.0426). With an average follow-up of 48 months (range, 38–62 months), the tantalum rod group had an 84.6 % survival rate. With an average follow-up of 72 months (range, 67–85 months), the control group had a 63.3 % survival rate. A comparison of Kaplan-Meier curves showed significantly higher cumulative survival rates (P?=?0.048) for hips with implantation of the porous tantalum rod (74.1 % at 62 months) than for those with impaction composite bone material (49.9 % at 62 months). The Cox proportional-hazard model revealed that implantation of tantalum rod (P?=?0.012), bone marrow edema (P?=?0.003), corticosteroids intake (P?=?0.007), and age less than 50 years (P?=?0.014) were the independent prognostic factors related to conversion into THA.

Conclusions

Compared with the traditional impaction composite bone material technique, implantation of tantalum rod in the treatment of Steinberg stages I and II ONFH can obtain better clinical results and higher cumulative survival rates. For patients without the use of corticosteroids, and especially for hips without bone marrow oedema, the clinical results from our study show highly encouraging survival rates and a delay in or prevention of conversion into THA.

     

Revision total hip arthroplasty using a cementless tapered revision stem in patients with a mean age of 82 years

Purpose

A tapered straight cementless stem was used for revision in a group of old and very old patients. We wanted to know whether the use of this implant could achieve satisfactory results despite age and osteoporosis.

Methods

We retrospectively analysed data of 77 elderly patients (77 hips) who underwent revision in cemented and uncemented primary total hip arthroplasties (THA). The patients had a mean age of 82.2 years (range, 75–92 years) at revision surgery. They were monitored for a mean follow up of 7.1 years (range, 5.0–10.2 years). During the minimum follow-up period 11 patients died of unrelated causes, leaving 66 patients (66 hips) for evaluation.

Results

During the period of study three stems failed due to aseptic loosening, three hips dislocated and were successfully treated by closed reduction and bracing. No infection, osteolysis or significant stress shielding around the stems was observed. The survivorship at an average of 7.1-year follow-up was 95.5%.

Conclusions

These results indicate that this stem is an excellent alternative in revision THA in patients of 75 years or older.