Objective

This study compared the primary stability of two commercially available acetabular components from the same manufacturer, which differ only in geometry; a hemispherical and a peripherally enhanced design (peripheral self-locking (PSL)). The objective was to determine whether altered geometry resulted in better primary stability.

Purpose

Primary internal fixation of uncomplicated scaphoid fractures offers many advantages compared to conventional casting. However, ideal fixation placement along the central scaphoid axis can be challenging, especially if the procedure is performed percutaneously. Because of the lack of direct visualization, percutaneous procedures demand liberal use of imaging, thereby increasing exposure to harmful radiation.

It has been demonstrated that computer-assisted navigation can improve the accuracy of guidewire placement and reduce X-ray exposure in procedures such as hip fracture fixation. Adapting the conventional computer-assist paradigm, with preoperative imaging and intraoperative registration, to scaphoid fixation is not straightforward, and thus a novel tactic must be conceived.

We report the use of a 15° face-changing cementless acetabular component in patients undergoing total hip replacement for osteoarthritis secondary to developmental dysplasia of the hip. The rationale behind its design and the surgical technique used for its implantation are described. It is distinctly different from a standard cementless hemispherical component as it is designed to position the bearing surface at the optimal angle of inclination, that is, < 45°, while maximising the cover of the component by host bone.

Dissociation of the polyethylene liner of modular acetabular components is a rare occurrence, and previous reports have commented on the difficulty in diagnosis from plain radiographs. The radiograph is often incorrectly reported by radiologists as showing advanced polyethylene wear, causing delay in referral and increasing the complexity of treatment required.

We report 9 cases of late polyethylene liner dissociation of the cementless Harris-Galante II porous-coated acetabular component (Zimmer Inc, Warsaw, IN) which occurred without trauma or injury. This is the largest reported series to date.

In all cases, there was a common pattern of clinical symptoms and signs which is described.

Radiographs showed a distinct appearance with a radiolucency medial to the femoral neck in association with an eccentrically placed femoral head lying in contact with the acetabular metal shell. We have termed this the ‘crescent sign’.

We believe that the diagnosis can be made from a single antero-posterior pelvic radiograph without the need for previous films for comparison, or the need for arthrography. Clinicians should look specifically for the crescent sign when an eccentrically placed femoral head has been noted, in order to differentiate the more unusual diagnosis of dissociation from that of polyethylene wear. Early diagnosis and prompt referral prevents further damage to the femoral head and metal acetabular shell, thus reducing the complexity of revision surgery.

There is a strong drive from industry, patients and the media to offer minimal access hip surgery (MAS) for joint arthroplasty. There is a plethora of definitions, implants, specialist instrumentation and techniques available. Confusion reigns as to the definition, who should offer it, which approach should be used, and what training should be undertaken.

Method : All Consultant Orthopaedic Surgeons in the United Kingdom were sent a simple questionnaire asking for MAS training undertaken, evidence of specialisation, volume of minimal access cases performed, availability of specialist instrumentation, approach used and definition of mimimal access surgery.

Results : 23% of those performing hip arthroplasty had performed MAS. The majority performed between 1–5 cases last year. 41% had observed MAS.

Of those with a specialist interest in hip arthroplasty, 37% had performed MAS.

Of those performing MAS, 83% had observed another surgeon and 60% had attended a course. 29% of consultants intend to perform MAS in the future. The mean and mode quoted length of a regular total hip arthroplasty scar was 15.4 and 15cm respectively. The mean and mode quoted length of a MAS scar was 9.7 and 10 cm respectively.

75% used the miniposterior approach.

Relationships with specialisation, British Hip Society membership and volume breakdown are discussed.

Conclusion: MAS is a popular technique although currently small case numbers are being performed. Given the level of interest in the technique, the definition and training required need to be clarified, and the clinical outcome requires close monitoring to ensure that standards of implantation are not jeopardised.

There has been a rapid uptake in the use of Resurfacing Hip Replacement (RHR) in the United Kingdom, and its use is likely to accelerate both in Europe and the USA. The current level of use of RHR is not accurately known.

It was decided to audit the use of RHR amongst Consultant Orthopaedic Surgeons in the United Kingdom, and to identify the number of operations performed in the last twelve month period, and the specific training undertaken before offering this procedure.

A questionnaire was sent to 1600 Consultant Orthopaedic Surgeons with 894 responding.

19% had performed RHR in the previous year.

Excluding surgeons that do not perform Total Hip Replacement, 23.5% of surgeons had performed RHR.

29.5% of all orthopaedic surgeons had observed RHR surgery and 23% had been on an RHR course. 65% of all consultants who had attended a course were offering RHR surgery.

7.8% of those performing RHR had neither been on a course nor observed surgery.

There was no relationship between years in practice and RHR surgery.

There was a weak association with British Hip Society membership and with a previous fellowship in Hip Surgery.

Of those performing RHR, 72% perform less than 20 cases per year. The majority of surgeons perform 6-10 RHRs per year.

Although interest in RHR is increasing, it is currently performed by the minority of consultants. Given the steep learning curve, the lack of knowledge of long-term survival, and concerns regarding metal on metal bearing surfaces, RHR should be used by surgeons with a specialist interest in hip arthroplasty. We believe RHR should be used in accordance with the guidance given by the National Institute for Clinical Excellence.

In the future, registration with a surgical speciality may require no more than the demonstration of core knowledge in the generality of that speciality and in the diagnosis and management of the related acute conditions. Sub-speciality training will be recognised separately. Rationalisation of referral patterns would then require that primary care practitioners are aware of these special abilities.

A questionnaire was sent to 1207 General Practitioners in the Avon, Leicestershire and Central London regions. The response rate was 86.2% (n = 1040). Views were sought on the management and referral of patients experiencing problems with existing hip replacements. These included the use of pre referral radiographs, whether practitioners would preferentially refer to a specialist hip surgeon and whether they believed that referral to a generalist could compromise patient care.

The majority GP’s arranged pre referral radiographs (84.2%). A third (34.2%) indicated that they would refer to any orthopaedic surgeon. 50.0% felt that outcome could be compromised if the patient was seen by an orthopaedic surgeon without a special interest in hip surgery.

There appears to be a need for more scientific information for GP’s and an agreed referral protocol. It is expected that rationalisation the referral system would lead to closer matching of patients needs with specialists’ abilities.