Thrust plate prosthesis for osteonecrosis of the femoral head: short-term results of 15 patients followed 2-6 years

[Short hip stem for THA in avascular necrosis of the femoral head]

INTRODUCTION

Osteonecrosis of the femoral head or avascular necrosis of the femoral head (HKN) is a complex disease that, without treatment, leads to infraction of the femoral head in most cases. In these cases, only replacement of the hip joint will help, although there is no clear recommendation of an arthroplasty type. In the last two decades, the treatment of primary and secondary coxarthrosis with short-shaft prostheses with different anchoring philosophies has increased. Since short-shaft fitting is a possible option especially in younger patients, the question arises about possible fittings of advanced HKN with these stem types, especially with metaphyseal anchorage. The aim of this study was to review the existing literature on the results of short stem prosthesis in HKN and to present the advantages and disadvantages of short stem prosthesis in osteonecrosis of the femoral head.

MATERIAL AND METHODS

This review analyzes the existing studies on short stem arthroplasty for HKN.

RESULTS

Only a few studies exist that have analyzed clinical and radiologic outcomes of short stem replacement in HKN.

CONCLUSION

The existing short- and medium-term results show mostly good outcomes. However, it is difficult to draw a general conclusion due to differences in stem design and fixation. Short stems with primary diaphyseal fixation do not show an increased risk of failed osseointegration or loosening. Constructions with primary metaphyseal fixation should undergo MRI to rule out the possibility of necrosis extending beyond the femoral neck.

Mid-term results of short stem total hip arthroplasty in patients with osteonecrosis of the femoral head

PURPOSE

To evaluate the clinical and radiographic mid-term results of short-stem total hip arthroplasty (THA) in patients with osteonecrosis of the femoral head (ONFH).

METHODS

We reviewed 83 cases that underwent Metha stem between November 2010 and November 2012. The appearance of bone trabeculae development and radiolucent line were reviewed and HHS was recorded at 6 months postoperatively then yearly to evaluate the clinical results.

RESULTS

The mean age of patients was 43.8 years with the mean follow-up 69.3 (60-84) months. Harris Hip Score improved significantly from 44.7 preoperatively to 99.6 at the last follow-up (p < 0.0001). There were 4 cases (4.8%) of intraoperative femoral fractures. There was 1 case (1.2%) of distal stem perforation that had stable bone ingrowth and there was 1 case (1.2%) of 5-mm subsidence, which was then stable at 3 months postoperatively. Bone trabecular development was detected at zone 1 (65.1%), 2 (69.9%), 3 (14.4%), 4 (1.2%), 6 (97.6%) and 7 (81.9%). There was 1 case (1.2%) where radiolucent lines were observed in zones 1 and 7. There was 1 femoral stem revision from periprosthetic fracture 4 years after index surgery and 1 cup revision from aseptic loosening. Kaplan-Meier survivorship with the end point of stem revision for any reason was 98.8% and for aseptic loosening it was 100% at 7 years.

CONCLUSIONS

The mid-term clinical and radiographic results of the Metha stem in patients with ONFH were promising. Its design enables preservation of the bone stock and the bone trabeculae appear to confirm the assumption of proximal force transmission.

Short-stem hip arthroplasty in osteonecrosis of the femoral head

INTRODUCTION

Osteonecrosis of the femoral head (ONFH) is a locally destructive and complex disorder. Without treatment, infraction of the femoral head is likely. There is also a lack of consensus in the literature about the most appropriate arthroplasty method in patients with progressive ONFH. During the last decade, the number of short-stem prostheses has increased. Some short-stem designs have a metaphyseal anchorage. It is questionable whether ONFH represents a risk factor for failure after implantation of short stems. The aim of this study was to review existing literature regarding the outcome of short-stem arthroplasty in ONFH and to present the pros and cons of short-stem hip arthroplasty in osteonecrosis of the femoral head.

MATERIALS AND METHODS

This review summarises existing studies on short-stem hip arthroplasty in osteonecrosis of the femoral head.

RESULTS

Few studies have analysed the clinical and radiological outcome of short-stem THA in patients with ONFH. Only a handful of studies present clinical and radiological outcome after implantation of a short-stem arthroplasty in patients with the underlying diagnosis of osteonecrosis of the femoral head.

CONCLUSION

The short- to medium-term results show predominantly good outcomes. However, due to differences in the design of short stems and their fixation, it is hard to draw a general conclusion. Short stems with primary diaphyseal fixation do not reveal a high increased risk of failed osseointegration or loosening. For designs with a primary metaphyseal anchorage, an MRI should be conducted to exclude that the ostenecrosis exceeds the femoral neck.

Short bone-conserving stems in cementless hip arthroplasty

➤ Short bone-conserving femoral stems in total hip arthroplasty were designed to preserve proximal bone stock.➤ Given the distinct fixation principles and location of loading among these bone-conserving stems, a classification system is essential to compare clinical outcomes.➤ Due to the low quality of currently available evidence, only a weak recommendation can be provided for clinical usage of certain stem designs, while some other designs cannot be recommended at this time.➤ A high prevalence of stem malalignment, incorrect sizing, subsidence, and intraoperative fractures has been reported in a subset of these short stem designs.➤ Stronger evidence, including prospective multicenter randomized trials comparing standard stems with these newer designs, is necessary before widespread use can be recommended.

Cementless short stem hip arthroplasty METHA® as an encouraging option in adults with osteonecrosis of the femoral head

INTRODUCTION

The implantation of a total hip arthroplasty is the standard treatment for patients with progressive osteonecrosis. However, there is uncertainty about the type of arthroplasty that provides the best outcome and whether short stem arthroplasty represents a reasonable alternative for young patients in order to have more options in case of revision. This uncertainty exists due to the lack of studies analysing contemporary short stem arthroplasty in osteonecrosis.

AIM

The aim of this study was to determine the outcome of the METHA(®) short stem arthroplasty in patients with progressive osteonecrosis.

PATIENTS AND METHODS

This study evaluated the clinical and radiological short- to midterm results after implantation of the cementless short stem arthroplasty METHA(®). 73 hips in 64 patients with progessive osteonecrosis after implantation of the METHA(®) arthroplasty were investigated by measuring the clinical outcome, the Harris Hip Score (HHS) and visual analogue pain scale for the preoperative stage and follow-up. Radiological analyses of X-rays were conducted to assess the bone ingrowth as well as subsidence, osteolysis or fracture.

RESULTS

The pain scale improved from preoperatively 7.8 to postoperatively 1.7, while the HHS increased from 41.4 to 90.6 points 34 months post-surgery. Complications associated with revision of the METHA(®) short stem included two traumatic femoral shaft fracture and one deep infection. The radiological assessment showed good bone ingrowth in all patients despite osteonecrosis.

CONCLUSION

The study confirms encouraging results as well as good bone ingrowth of the cementless short stem arthroplasty METHA(®) even in patients with osteonecrosis.

The thrust plate prosthesis in the treatment of osteoarthritis of the hip. Clinical and radiological outcome with minimum 5-year follow-up

The thrust plate prosthesis (TPP) is a neck preserving femoral component in total hip arthroplasty (THA). We present our mid-term results from using the thrust plate prosthesis in young patients with hip arthritis. We conducted a retrospective review of a consecutive series of patients with a minimum of 5 years follow-up after total hip arthroplasty using the thrust plate prosthesis. Harris Hip Score (HHS) and Oxford Hip Score (OHS) were recorded preoperatively and at the last clinical review. Radiographic analysis was performed and patient satisfaction levels and complications were recorded. Between 1996 and 2000 we implanted 41 prostheses in 38 consecutive patients (3 bilateral). The mean age at time of surgery was 56 years (41-67) and the mean length of follow-up was 71 months. The HHS improved from a mean of 42 points preoperatively to 88 points at the last clinical review and the mean OHS also improved from 40 points to 18 points. Eighty-three percent of patients expressed that they were 'very satisfied' with the procedure. Implant survivorship was 95% at 5 years follow-up with revision surgery being the end point. Eight patients suffer discomfort when lying on the operated side. Many patients treated with the TPP show excellent improvement in clinical outcome scores and a high level of patient satisfaction but the complication rate gives some concern. We support the selective use of the TPP to treat young patients with hip osteoarthritis.

Clinical and radiological mid-term results of the thrust plate prosthesis

The purpose of this study was to perform an objective clinical and radiological assessment of the thrust plate prosthesis (TPP). Fifty-three prostheses were evaluated clinically using the Harris hip score (HHS), visual analog scale (VAS), and radiographically before surgery, at the time of discharge, and postoperatively after on average of 8.09 (range 4.61-9.93) years. The average HHS significantly (p < or = 0.05) improved from 48 (range 18-77) points to 95 (range 46-100) points. The VAS revealed significant (p < or = 0.05) reduction of pain at rest and under load. Radiographic analysis showed a considerable potential for osteolysis under the thrust plate. Sixteen prostheses revealed signs of radiolucent zones. In general, there was a good clinical outcome with no major limitations in function. Radiographic changes under the thrust plate indicate an adaptation processes resulting from changed biomechanics. This study suggests that the TPP could be a good alternative in total hip replacement in younger patients.