The Birmingham hip resurfacing (Smith & Nephew, Tennessee) (BHR) has been used in younger more active patients.

Aim

Adverse tissue reactions have been a concern in relation to metal components, particularly in hip replacements. We look at a possible correlation between hip joint effusion and metal ion levels.

There has recently been an increase in the number of hip replacement procedures performed through an anterior approach. Every procedure has a risk profile, and in the case of a new procedure or technique it is important to investigate the incidence of complications. The aim of this study is to identify the complications encountered in the first 100 patients treated with the minimally invasive anterior approach.

This is a case series of the first 100 hips treated and were assessed for complications. These were classified according to the severity and outcome [1]. The 100 hip comprised of 98 patients; 46 males and 52 females with an average operation age on 70.1 (±9.38) years. There were 2 bilateral procedures. Specific patient selection criteria were used. All complications occurred within one month of surgery. Complications such as fracture, deep vein thrombosis (DVT), cup malposition, femoral stem malposition, retained screw, excessive acetabular reaming and skin numbness were noted. Complications associated with fracture were characterized as either periprosthetic or trochanteric. Clinical outcome scores of SF36v2, WOMAC, Harris Hip and Tegner activity score were analysed at pre-operative, 6 months, 12 months 24 months and 36 months intervals.

A total of 13 early complications occurred. Of these 13 complications the most common complications were trochanteric fracture, 3 instances (3.00%), periprosthetic fracture, 2 (2.00%), DVT, 2 (2.00%), numbness, 2 (2.00%) and loosening. Other complications recorded were cup malposition, 1 (1.00%), femoral stem malpositon, 1 (1.00%), retained screw, 1 (1.00%) and excessive acetabular reaming, 1 (1.00%). All fractures occurred in patients over the age of 60 years.

Significant differences (p<0.05) were observed between all clinical outcomes measures pre-operatively and postoperatively (6, 12, 24 and 36 months). The unfamiliarity of the approach, however, increased operating time, and exposure problems, lead to trochanteric fracture.

Introduction

Dissatisfaction with the posterior approach to total hip replacement has led to the anterior approach being adopted with enthusiasm in some areas.

Introduction

The observation of elevated heavy metal ions in arthroplasty patients in association with complications has led to concern on the part of patients and surgeons. The aim of this study was to determine the levels of cobalt chromium ions in three compartments, the joint fluid, plasma, and CSF.

Comparisons of blood metal ion levels of cobalt and chromium (CoCr) between metal-on-metal total and resurfacing hip arthroplasties are limited. High levels of CoCr may result in long-term adverse biological effects. We compare metal ions levels between total and resurfacing implants.

70 patients (28 males and 42 females) had a total hip arthroplasty using the Birmingham (Smith & Nephew) modular femoral component and a variety of stems, articulating with the Birmingham resurfacing component. The average age was 65.5 (±6.8) years and an average follow-up of 6.0 (±2.2) years. 170 patients (145 male and 25 female had a Birmingham resurfacing arthroplasty with an average age of 54.7 (±9.9) years and an average follow-up of 5.9 (±3.0) years. CoCr levels were measured. Bivariate correlations and independent samples t-tests were applied to determine similarities and differences within and between groups.

Average ion levels in total arthroplasty patients were: Co 114.17 (±94.01) nmol/L (range 2–414); and Cr 75.12 (±68.45) nmol/L (range 10–312). Average levels in hip resurfacing arthroplasty were: Co 55.98 (±79.5) nmol/L (range 7–505); and Cr 70.77 (±87.41) nmol/L (range 5–751). Both total and resurfacing groups showed significant correlations (p<0.01) between Co and Cr levels. A significant difference was observed between the total and resurfacing group Co levels (p<0.0001). No significant difference was shown between group Cr levels (p>0.672).

The average total hip replacement CoCr levels were higher than the hip resurfacing levels. While the overall activity level may be higher in the resurfacing group, possibly the incidence of stop/start frequency may be higher in the total hip replacement group.

Hip resurfacing arthroplasty average CoCr levels are lower than those of total hip replacement patients. Associations between Co and Cr metal ion levels are shown within each group. Co levels differ significantly between groups where Cr does not. Long-term follow-up of CoCr levels are required.

The Repicci modification of the Marmor unicompartmental arthroplasty (UKA) has provided a minimally invasive alternative to proximal tibial osteotomy for localised osteoarthritis. Advantages of UKA include preservation of bone, faster rehabilitation and maintained function. This study analyses the survivorship of the Repicci medial compartment arthroplasty with a minimum 10-year follow-up.

438 medial UKR procedures were performed between 01/01/1998 and 01/07/2001 included 68 bilateral procedures in 370 patients. The patients comprised of 229 males and 141 females. A specific set of selection criteria were used, including clinical, radiological, an arthroscopic data. The average age at operation was 66.7 years. The average follow-up was 12.8 years. For the patients who are not reachable, we sought the help of the Australian joint replacement registry. All revisions were identified. Procedures were reviewed to determine survivorship and function. Clinical outcomes scores of SF36v2. WOMAC and Oxford Knee were analysed at pre-operative, 1, 3, 5 and 10 year intervals.

In 54 patients (64 procedures) the implant was in situ at the time of death. Revision was carried out in 37 knees (8.5%) at a mean time period of 7.8 years (1–13) post-operatively. Of the revisions, the commonest cause was progression of arthritic changes in the lateral compartment, 25 patients. Loosening of the tibial component was present in six patients and for six patients whose data was obtained from the registry, revision was documented, but no cause was identified. Kaplan-Meier investigation showed survivorship of 91.6% to 12.5 years. Average pre-operative, 1, 3, 5 and 10 years SF36v2 Total scores were 107.80, 124.57, 124.83, 111.14 and 121.47. WOMAC Total scores for pre-operative, 1, 3, 5 and 10 years were 51.96, 83.34, 80.59, 82.00 and 78.54. Oxford Knee scores for pre-operative, 1, 3, 5 and 10 years were 35.76, 20.99, 19.28, 19.61 and 21.16.

Significant differences (p<0.0001) were observed between all pre-operative and post-operative 1, 3, 5 and 10 year outcomes of SF36v2, WOMAC and Oxford Knee scores.

UKR is an operation which is often regarded as a temporising procedure, on the way to a total knee replacement, the attrition rate is less than 1% per year, indicates that long-term function is a goal which may be achievable.

UKR provides satisfactory function, with a low revision rate, and a minimally invasive approach does not decrease the efficacy, while currently, improving function, speed of recovery, and patient satisfaction. Patient selection, particularly in relation to the status of the lateral compartment articular surface may be an important aspect in minimising revision incidence.

The Birmingham mid-head hip resurfacing arthroplasty (Smith & Nephew, Tennessee) (BMHR) is designed for use in patients with avascular necrosis of the femoral head. The BMHR has limited short-mid term follow-up results. We report the experience of 27 consecutive BMHR procedures with a minimum two year follow-up.

23 patients (20 males and 3 females) with an average operation age of 49.8 years (SD ±10.9) (22–65) were investigated. The mean follow-up period was 3.0 years (SD ±0.77). The operations were between April 2008 and November 2011 by one surgeon. Data and outcome measurements were collected prospectively and analysed retrospectively. Procedures were reviewed to determine function. We evaluated Harris Hip Scores, Short Form-36 (SF-36v2) Scores, Tegner Activity Score Scores and McMaster Universities Osteoarthritis Index Scores (WOMAC) comparatively at preoperative, six month and yearly intervals. Paired samples t-tests were applied to determine improvements where p<0.05 was deemed as significant.

There were no patient deaths. There were no revisions. Harris Hip scores for pre-operative 6, 12, 24 and 36 month intervals were: 52.30, 84.14, 83.07, 87.50 and 89.50. Average pre-operative 6, 12, 24 and 36 month SF36v2 Total scores were: 116.54, 124.32, 130.44, 135.97 and 133.18. Tegner scores for pre-operative 2.75, 3.29, 3.00, 3.67 and 3.01. WOMAC Total scores for aforementioned intervals for the posterior approach were: 59.51, 84.22, 90.30, 86.86 and 92.25.

The mean Harris Hip scores improved significantly between preoperative and 6, 12, 24 and 36 months (p<0.001). The mean SF-36v2 physical scores improved significantly between preoperative and 6, 12, 24 and 36 months (p<0.016). WOMAC scores improved significantly between preoperative and 6, 12, 24 and 36 months (p<0.017).

The presence of avascular necrosis significantly increases the revision rate for hip resurfacing surgery. The BMHR prosthesis, in this short term follow-up, appears to avoid the main cause of failure, femoral component loosening. Longer term efficacy remains to be seen. We plan to continue close supervision of these patients.

The Birmingham Hip Resurfacing (BHR) has been used in the younger more active patient for the treatment of advanced osteoarthritis. Long-term follow-up of the BHR is limited. The Australian national joint replacement registry shows that failure rates vary greatly, depending on implant types. 77 consecutive BHR procedures with a minimum ten year follow-up are reported.

There were 70 patients (44 males and 26 females) with an average operation age of 57.4 years (SD ±12.6). All patients were evaluated, including the “learning curve” patients. The mean follow-up period was 11.42 years (SD ±0.50). The arthroplasties were performed between April 1999 and December 2000 by one surgeon, with a standardised patient selection set of criteria. Data and outcome measurements were collected prospectively and analysed retrospectively. We evaluated Harris Hip Scores, Short Form-36 (SF-36v2) Scores, Tegner Activity Score Scores and McMaster Universities Osteoarthritis Index Scores (WOMAC) comparatively at preoperative, six month and yearly intervals

In 8 patients (10 procedures) the implant was in situ at the time of death. Revision was carried out in 6 hips (7.8%) at a mean time period of 2.5 years (0–10) post-operatively. Failure was due to femoral neck fracture in four patients, acetabular loosening in one and avascular necrosis of the femoral head, leading to loosening, in one patient. Kaplan-Meier analysis showed survivorship of 92.2% to 10 years. The mean Harris Hip scores (paired t-test, p<0.05) improved significantly from 59.7 preoperatively to 80.1 at ten years. The mean SF-36v2 physical scores (paired t-test, p<0.05) improved significantly from 35.09 preoperatively to 47.83 at ten years. WOMAC scores (paired t-test, p<0.05) improved significantly from 54.61 preoperatively to 85.89 at ten years.

The BHR prosthesis, in this series, has been shown to be effective, reliable, and durable in this group of highly active, relatively young patients. Problems with metallic debris, sensitivity reactions, and osteolysis have not been seen. However, we believe that with better selection criteria, improved understanding of component positioning and surgical techniques, results can be improved.

There is a report that higher failure rate in uncemented total knee replacement components due to loosening. However, uncemented fixation has been an attractive concept because of bone preservation and revision surgery, potential improved load transfer, and decreased surgical time. “Regenerex” is a porous titanium layer with excellent initial fixation, and the promise of providing favourable biological fixation. This is used with the Biomet Vanguard total knee replacement.

14 patients had undergone total knee replacement surgery comprising 11 men and three women with an average age of 63.07 years, and a body mass index of 30.33. Three of these patients required revision, because of tibial component loosening within 12 months of surgery. There were two men and one woman with an average age of 63.33 and BMI of 34.55. Clinically, patients developed pain and a gradual deformity as a result of a symmetrical collapse of the proximal tibial bony support surface.

Histopathology on the removed specimens shows the development of fibre cartilaginous metaplasia with evidence of necrotic bone. This was similar in all patients. There was no foreign body giant cell reaction, and no evidence of infection. The appearance was suggested of osteonecrosis, occurring gradually.

The incidence of frequency of this complication with this component in our experience is of concern, and the aim of this presentation is to determine whether this is a more widespread phenomenon.

There has recently been an increase in the number of hip replacement procedures performed through an anterior approach. Every procedure has a risk profile, and in the case of a new procedure or technique it is important to investigate the incidence of complications. The aim of this study is to identify the complications encountered in the first 100 patients treated with the minimally invasive anterior approach.

This is a case series of the first 100 hips treated and were assessed for complications. These were classified according to the severity and outcome [1]. The 100 hip comprised of 98 patients; 46 males and 52 females with an average operation age on 70.1 (±9.38) years. There were 2 bilateral procedures. Specific patient selection criteria were used. All complications occurred within one month of surgery. Complications such as fracture, deep vein thrombosis (DVT), cup malposition, femoral stem malposition, retained screw, excessive acetabular reaming and skin numbness were noted. Complications associated with fracture were characterised as either periprosthetic or trochanteric. Clinical outcome scores of SF36v2, WOMAC, Harris Hip and Tegner activity score were analysed at pre-operative, 6 months, 12 months 24 months and 36 months intervals.

A total of 13 early complications occurred. Of these 13 complications the most common complications were trochanteric fracture, 3 instances (3.00%), periprosthetic fracture, 2 (2.00%), DVT, 2 (2.00%), numbness, 2 (2.00%) and loosening. Other complications recorded were cup malposition, 1 (1.00%), femoral stem malpositon, 1 (1.00%), retained screw, 1 (1.00%) and excessive acetabular reaming, 1 (1.00%). All fractures occurred in patients over the age of 60 years. There were no dislocations.

Significant differences (p<0.05) were observed between all clinical outcomes measures pre-operatively and postoperatively (6, 12, 24 and 36 months). The unfamiliarity of the approach, however, increased operating time, and exposure problems, lead to trochanteric fracture.