Direct anterior approach (DAA) arthroplasty has generated great interest because of its minimally invasive and muscle sparing nature. Obese patients are reported to be associated with greater incidence of complications in primary joint replacement. The purpose of this study was to compare patient outcomes and complication rates between obese and non-obese patients undergoing primary total hip arthroplasty (THA) through a Bikini direct anterior incision.

This retrospective, single surgeon study compared the outcome of 258 obese patients and 200 non-obese patients undergoing DAA THA using a Bikini incision, over a 7-year period. The average follow-up was 4.2 years (range 2.6-7.6 years).

There were no statistically significant differences in the complication rate between the two groups. The obese group recorded 2 major (venous thromboembolism and peri-prosthetic fracture) and 2 minor complications (superficial wound infection), compared with the non-obese group, which recorded 2 major (deep-wound infection and peri-prosthetic fracture) and 1 minor complication (superficial wound infection). Patient-reported outcomes (WOMAC and Harris Hip Scores) showed significant post-operative improvements (p < 0.001) and did not differ between the two groups.

Bikini DDA THA does not increase the complication rate in obese patients and offers similar clinical improvements compared to non-obese patients.

(200 words)

The purpose of this study was to report all complications during the first consecutive 865 cases of bikini incision direct anterior approach (DAA) total hip arthroplasty (THA) performed by a single surgeon. The secondary aims of the study are to report our clinical outcomes and implant survivorship. We discuss our surgical technique to minimize complication rates during the procedure.

We undertook a retrospective analysis of our complications, clinical outcomes and implant survivorship of 865 DAA THA's over a period of 6 years (mean = 5.1yrs from 2.9 to 9.4 years).

The complication rates identified in this study were low. Medium term survival at minimum 2-year survival and revision as the end point, was 99.53% and 99.84% for the stem and acetabular components respectively. Womac score improved from 49 (range 40-58) preoperatively to 3.5(range 0-8.8) and similarly, HHS scores improved from 53(range 40-56) to 92.5(range 63-100) at final follow-up (mean = 5.1 yrs) when compared to preoperative scores.

These results suggest that bikini incision DAA technique can be safely utilised to perform THA.

INTRODUCTION

The Woodpecker pneumatic broaching system facilitates femoral preparation to achieve optimal primary fixation of the stem in direct anterior hip replacement using a standard operating table. The high-frequency axial impulses of the device reduce excess bone tension, intraoperative femoral fractures and overall operating time. The Woodpecker device provides uniformity and enhanced control while broaching, optimizing cortical contact between the femur and implant and thereby maximizing prosthetic axial stability and longevity. This study aims to describe a single surgeon's experience using the Woodpecker pneumatic broaching system in 649 cases of direct anterior approach (DAA) total hip arthroplasties to determine the device's safety and efficacy.

INTRODUCTION

The primary goal of THA or TKA is to relieve pain and restore mobility. The success is determined by the longevity of prostheses and early return to routine activities, such as driving. With enhanced recovery regimens, patients are being discharged within 24–48hrs post-op.. The aim of this study was to determine when our patients returned to driving after anterior hip replacements and patient specific knee replacements.

BACKGROUND

We conducted this study to determine if the pre-surgical patient specific instrumented planning based on Computed tomography scans can accurately predict each of the femoral and tibial resections. The technique helps in optimization of component positioning and hence overall alignment thereby reducing errors. This makes it less invasive, more efficient and cost effective. The surgical plan in combination with the cutting guides determine the resection thickness, component size, femoral rotation and femoral and tibial component alignment. Several clinical studies have shown that PSI is safe, accurate and reproducible in primary TKA. Accurate preparation of the femoral and tibial surfaces will determine alignment and component positioning and this in turn reflects on function and longevity

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.

Introduction:

Periprosthetic joint infection (PJI) is a devastating diagnosis that carries a significant rate of associated mortality and places a large burden on health care systems. Treatment protocols often include combined intravenous antibiotics and staged revision surgery with locally-delivered antibiotics via PMMA cement spacers and/or beads. One disadvantage of PMMA is the need for later removal. Antibiotic releasing Calcium Sulphate beads (CaSO₄) have had promising results in revision joint surgery and are absorbable, making later removal unnecessary. We report on use in a tertiary referral centre in the UK and present our initial findings.

Although effects of mechanical stimulation with high frequency, low magnitude vibrations on bone mass and bone mineral density in animal and clinical studies have been proven effective, its effects on fracture healing is less well described.

20 Sham and 20 ovarectomised (Ovx) Sprague Dawley rats at 22 weeks of age, had intra-medullary k-wire fixation followed by controlled mid-shaft fractures.

The animals were divided into subgroups of 3 week Sham and Ovx treated and non-treated and 6 week Sham and Ovx treated and non-treated groups.

The treated animals were vibrated for 20mins daily on a DMT (dynamic motion therapy) platform which had a frequency of 30hz, 8-micron vertical displacement and 3g force, the non treated animals allowed to move freely. Xrays, DEXA studies, micro computed tomography, Histological analysis and Mechanical studies performed at the end point.

DMT treated animals had more bridging callus on radiographic and micro computed tomographic analysis compared to non-treated groups especially the OVX groups at 3 weeks compared to controls or Shams (using Image J software). DEXA studies showed increased bone mineral density and bone mineral content in the treated animals compared to the controls. Histological analysis showed increased callus and woven bone being laid down in the treated OVX groups.

In the 6-week groups, the treated OVX groups had healed, remodelled fractures compared to the non-treated groups or Sham controls where the fracture gaps were still visible. Although significance was not achieved on mechanical analysis due to small sample size, in the OVX non-operated femora group that were treated with DMT there were indications that they were stronger than the control counterparts.

High frequency low magnitude vibrations with the Juvent DMT device enhances fracture healing in oestrogen deficient models and this model could be used as a platform for clinical studies in future.

Pain relief in hip arthroplasty plays an important role in the intra/post operative stages in order to achieve an almost pain free post operative recovery period to mobilise the patient as early and safely as possible and avoid undesirable post surgical complications.

A consecutive series of 99 total hip arthroplasties in 93 patients performed by a single surgeon between December 1996 and January 2006 were assessed for signs of clinical or radiological loosening.

Intra-operative local anaesthetic mixture (Ropivacaine-Ketorolac (30mg) -Adrenaline or RKA mixture) was infiltrated into the joint capsule and surrounding tissue around the acetabular component, and into the different muscle layers in the thigh around the femoral component. A total of 150–200 mls of this mixture was injected and a further 50 mls (with 30mg ketorolac) injected through a catheter left in-situ before discharge 12 to 24 hours later. Radiographic analysis was carried out using the Hodgkinson criteria to predict acetabular component loosening and the Gruen method to determine femoral component loosening.

Of the 99 hybrid hips, 57 were right and 42 were left hip arthroplasties and 6 patients had bilateral consecutive hips done. 5 were performed for revision of fractured necks of femur in Birmingham hip resurfacings and one total hip arthroplasty revised to a hybrid and the remaining 92 were primary hybrid hip arthroplasties. The arthroplasties were performed for Osteoarthritis (89), Rheumatoid arthritis (4), and others (6). At mean follow up of 4.2 years, no aseptic loosening was noted radiologically or clinically, no components have been revised for failure or loosening and no components have dislocated.

The use of high dose local infiltration NSAIDs in the intraoperative and early post operative phase does not seem to affect prosthetic fixation at-least during short to mid term follow up of total hip joint arthroplasties.

This bone preserving procedure is less well described in the much older population over 65 years of age. Despite good bone quality, independence and active lifestyle, older age seems to be a deterrent for hip resurfacings among most orthopaedic surgeons.

Analysis of 111 Birmingham hip resurfacings in 105 consecutive patients from 1999 to 2007 performed by a single surgeon was carried out to determine radiological and clinical outcome. The unique selection criteria looked at joint disease, activity levels, general health, imaging (Xray/CT/MRI) and Bone density studies.

28 females and 77 males with mean age of 69.5 years (65–87 years, SD +/− 4), body mass index of 27.2 (19–40.4, SD +/− 3.8) underwent resurfacings. 8 patients had bilateral, consecutive 2 stage procedures. Mean Follow up was 3.8 years ranging from 3 months to 7 years. 62 resurfacings were performed in the age group 65–69 yrs, 32 resurfacings in the 70–74 age group, 12 resurfacings in the 75–79 age group and 4 resurfacings in the 80–89 age group. 77 patients (71.3%) stayed one night or less in hospital. 4 patients (3 males and 1 female) had postoperative fracture neck of femora.

Radiographic review at the most recent follow up revealed non of the patients (101) who had the original hip resurfacing components had any evidence of gross loosening, migration or subsidence requiring revision of either the cup or the femoral components. No patients complained of localised hip pain and at the most recent follow up they had very good to excellent function with no report of dislocations.

Hip resurfacing is a challenge in patients who are over the age of 65 years. Using our selection criteria, it may be offered to active, independent patients with good bone quality as this age group in the population becomes larger with time.

Birmingham Hip resurfacings have been a popular mode of treatment for younger and more active patients with arthritis of the hip. However the use of hybrid hip arthroplasty system with a Birmingham hip resurfacing cup and modular head with a variety of cemented/uncemented stems is less well described in the literature.

We analysed radiographic and clinical outcomes of 99 consecutive hybrid hip arthroplasties performed by a single surgeon between 2000 and 2006.

A total of 93 patients (52 females and 41 males) with an average age of 69.9 (47 to 88) and average BMI of 28.8 (18.7 to 140.9) had arthroplasties with a mean follow up of 4.1 Yrs (1 to 6.3 years). 57 right and 42 left hip arthroplasties were performed of which 6 patients had bilateral consecutive hybrid hip arthroplasties.

93 were performed for osteoarthritis, 4 for RA, 5 patients for revision of failed hip resurfacing arthroplasties with #NOF and 1 revision for failed THR.

No patients had dislocations and one patient had revision of a resurfacing cup secondary to hip pain due to excessive cup anteversion, no loosening of components were identified at the most recent follow-up and all patients were mobilising well with no complaints of pain.

Hip Resurfacing procedures are gaining popularity in the younger individuals with arthrosis of the hip. Some patients who are fairly independent and active fall short of satisfying the criteria for a hip resurfacing and we preferred the option of the Birmingham hip resurfacing cup with a large modular head and a compliment of stems. This metal-on-metal option with large heads would ideally increase stability and reduce wear patterns with the prospect of increasing longevity of total hip arthroplasties.