Aim: This study was performed to review the early results of the use of a semi-constrained acetabular component in the treatment of recurrent hip dislocation at Palmerston North Hospital. Method: A retrospective case study of patients who underwent acetabular component revision with a semi-constrained cup for recurrent dislocation of the hip was performed. Results: Between April 1999 and July 2000, 10 patients with an average age of 75 years underwent acetabulum revision with a semi-constrained cup. There was an average of four dislocations before revision surgery, per patient. At follow-up between three and 18 months after the revision, there had been no dislocations. Aggressive post-operative rehabilitation was permitted, allowing discharge at an average of seven days postoperatively. Conclusion: The use of a semi-constrained acetabular cup was successful as a means of treatment for recurrent hip dislocation. This is an early review of the use of the implant. There are no published data on long term survival of this implant. The semi-constrained cup provides a simple yet effective option for dealing with the elderly recurrent hip dislocation

Although the incidence of total hip dislocation has decreased, it still remains a major problem particularly if recurrent. The actual incidence is around 1–2% but it has been documented as the leading cause for hip revision in the United States. In patients with recurrent hip dislocation, technical issues of leg length inequality, incorrect offset, and poor implant position should be addressed surgically and the abnormality corrected. In patients with recurrent hip dislocation, the articulation is preferably converted to a more stable articulation, with constrained sockets and dual mobility being the choices. In my experience, dual mobility articulations remain an excellent option for recurrent hip dislocation and its use is increasing significantly. It provides improved hip stability and data have demonstrated good success with recurrent hip dislocation. However, with use of the modular variety of dual mobility which is needed for acetabular cup fixation with screw augmentation, dissimilar metals are placed in contact (titanium socket and cobalt chrome liner insert) which potentially can pose a fretting or corrosion problem in longer term outcomes. Constrained sockets of the tripolar configuration provide another option which is useful in those patients with severe abductor dysfunction or insufficiency. Constrained sockets can also be cemented into the existing shell in cases where there is a well-fixed cup and cup removal may lead to significant bone loss and a need for complex acetabular reconstruction. It is important to remember that there are two types of constrained sockets, tripolar and focal constraint. Results with the tripolar constrained socket have been significantly better than the focal constraint variety which adds a polyethylene rim piece to the liner. In a mid-term follow up (2–9 years) of 116 constrained tripolar sockets, recurrent dislocation was only 3.3%. In papers reporting on focal constrained sockets, recurrent dislocation was in the 9–29% range. There continues to be a role for constrained sockets and selection of implant type has made a difference in ultimate outcome

Although the incidence of total hip dislocation has decreased, it still remains a major problem particularly if recurrent. The actual incidence is around 1–2% but it has been documented as the leading cause for hip revision in the United States. In patients with recurrent hip dislocation, technical issues of leg length inequality, incorrect offset, and poor implant position should be addressed surgically and the abnormality corrected. In patients with recurrent hip dislocation, the articulation is preferably converted to a more stable articulation, with constrained sockets and dual mobility being the choices. In my experience, dual mobility articulations remain an excellent option for recurrent hip dislocation and its use is increasing significantly. It provides improved hip stability and data have demonstrated good success with recurrent hip dislocation. However, with use of the modular variety of dual mobility which is needed for acetabular cup fixation with screw augmentation, dissimilar metals are placed in contact (titanium socket and cobalt chrome liner insert) which potentially can pose a fretting or corrosion problem in longer term outcomes. Constrained sockets of the tripolar configuration provide another option which is useful in those patients with severe abductor dysfunction or insufficiency. Constrained sockets can also be cemented into the existing shell in cases where there is a well-fixed cup and cup removal may lead to significant bone loss and need for complex acetabular reconstruction. It is important to remember that there are two types of constrained sockets, tripolar and focal constraint. Results with the tripolar constrained socket have been significantly better than the focal constraint variety which adds a polyethylene rim piece to the liner. In a mid-term follow up (2–9 years) of 116 constrained tripolar sockets, recurrent dislocation was only 3.3%. In papers reporting on focal constrained sockets, recurrent dislocation was in the 9–29% range. There continues to be a role for constrained sockets and selection of implant type has made a difference in ultimate outcome

Early reports on revision total hip arthroplasty (RTHA) suggested that outcomes of this procedure are as good as those of primary total hip arthroplasty (THA). However, RTHA is associated with longer surgery time, greater blood loss and increased risk of complications (thromboembolism, nerve injury, periprosthetic fractures, recurrent hip dislocations and infections). Aseptic loosening after RTHA was reported in 36% of patients aged over 55 years within 4 years after revision. Infections were reported in 32% and complications during surgery in 23% of patients respectively. Unsatisfactory results of RTHA stimulate the search for alternative procedures. Girdlestone excision arthroplasty (GA) seems to be a good solution for older patients with high risk of complications related to a poor general condition. Material and method Between 2000 and 2003 we operated 39 patients, 10 for septic (26%) and 29 aseptic (74%) loosening of their THA. All patients complained of painful limb aggravated by weight bearing and the severity of pain was the main indication for the surgery. Average survival time of previous THA was 9 year (range: 1 to 20). We assessed pain, walking distance and the need to use walking aids. The outcomes were measured according to the Harris Hip Scale. The patients had the GA performed. The procedure involved removing implant and bone cement and placing the major trochanter into bone acetabulum. If an infection was present, an antibiotic irrigation system was introduced. No cast or braces were used and walking was started 2–7 days after surgery, depending on patients general condition. Results Good pain control was reported by 33 (85%) patients. The average Harris Hip Score changed from 25 points preoperatively to 53 at latest follow-up. Average limb shortening was 4 centimetres (range: 2 to 8). Walking aids (one or two crutches) were required by all patients. Eighteen (46%) patients walked more than 500 m, 12 (31%) patients walked 200–500 m and 9 (23%) patients walked less than 200 m, of whom one patient was wheelchair bound. Infection ceased in 9 cases, 1 patient died because of complications related to chronic infection. Discussion GA yields satisfactory results in patients who have to have their prostheses removed. It provides a mobile, painless joint. The disadvantages of GA are: limb shortening and unstable gait which requires the use of crutches. This procedure should be indicated for patients with high risk of complications due to poor general health, infection and/or massive loss of bone stock which render more invasive procedures impossible. GA is also advisable in patients with weak hip abductor muscles, when RTHA is associated with a high risk of recurrent hip dislocation. The Girdlestone arthroplasty is a satisfactory salvage procedure in most cases of failed THA, when the choice of reimplantation exposes the patient to a high risk of further failure

Introduction. Revision surgery is generally recommended for recurrent dislocation following Total hip arthroplasty (THA). However, dislocation following revision THA continues to remain a problem with further dislocation rates upto 28% quoted in literature. We present early results of one of the largest series in U.K. using dual mobility cemented acetabular cup for recurrent hip dislocation. Methods. We retrospectively evaluated 40 patients where revision of hip replacement was performed using cemented dual mobility acetabular prosthesis for recurrent dislocations from March 2006 till August 2009 at our district general hospital by a single surgeon (senior author). The series comprised of 13 men and 27 females with average age of 73.4 years (49-92). The mean follow-up period was 23 months. (36 months –6 months). All the hips that were revised had 3 or more dislocations, some them more than 10 times. The cause of dislocation was multifactorial in majority of cases including acetabular component malpositioning mainly due to loosening and wear. A cemented dual mobility cup was used in all cases. In six cases the femoral stem was also revised. Results. At mean follow up of 26 months none of the revised THA had dislocated nor did they have any features of instability. No patients were lost for follow up. Clinically and radiologically there were no features of loosening of the acetabular component. Discussion. The dual mobility cup appears to be a reliable method in treatment for recurrent total hip dislocations. Although our early results are encouraging with no loosening of acetabular components a further evaluation at longer follow- up is recommended

Dual mobility components for total hip arthroplasty provide for an additional articular surface, with the goals of improving range of motion, jump distance, and overall stability of the prosthetic hip joint. A large polyethylene head articulates with a polished metal acetabular component, and an additional smaller metal head is snap-fit into the large polyethylene. The first such device was introduced for primary total hip arthroplasty by Bousquet in the 1970s, thus, the “French connection”. Dual mobility components have been released for use in North America over the past five years. In some European centers, these components are routinely used for primary total hip arthroplasty. However, their greatest utility may be to manage recurrent dislocation in the setting of revision total hip arthroplasty. Several retrospective series and the Swedish hip registry have shown satisfactory results for this indication at short- to medium-term follow-up times. However, there are important concerns with polyethylene wear, late intraprosthetic dislocation, and the lack of long-term follow-up data. These components are an important option in the treatment of recurrent dislocation in younger patients, revision of failed metal-metal resurfacing, and salvage of failed constrained liners. There are more recent concerns of possible iliopsoas tendinitis, elevated metal levels with one design, and acute early intraprosthetic dislocation following attempted closed reduction. However, a dual mobility component may now be the preferred solution in revision surgery for recurrent hip dislocation

Uncemented double-mobility acetabular cups, first used in the late 1970s as a solution to recurrent hip dislocations, have proved efficient in reducing dislocation rates while preserving an important range of motion. The low wear-rate and low mechanical stress on the bone to cup interface enhances survival. New instrumentation has permitted design changes that improve the dislocation coverage of the cup (upper part of the cup) and reduce the risk of impingement with the femoral stem (lower part of the cup). Indications for the use of double-mobility cups have increased. They include primary total hip arthroplasty in relatively unstable hips, in which cases we use the Avantage® press-fit or 3P cup with an AURA II anatomical uncemented or cemented stem, dysplasia (in congenital high dislocations we use the press-fit or 3P or revision cup with an AURA revision stem, and in dysplasia we use small AURA II or Vectra or CMK dysplastic stems), muscular deficiency, in which Avantage® cups can be used with AURA II or revision stems, resection prosthesis or ARMEL calcar prosthesis, etc.)

Purpose. Overall outcome of bilateral hip and knee arthroplasty in the same patient with special regard to scheduling, postoperative complications and follow-up under consideration of the underlying disease. Method. More than 6000 primary THA and 5500 primary TKA were implanted at Schulthess Clinic since 1985, 8% of which in rheumatoid patients. Quadruple THA and TKA was performed in a total of 51 rheumatoid patients. Mean follow-up for knees was 8. 5 years (1–17), and 9. 5 years (1–18) for hips. 67% of implants were uncemented. In 21% of patients, all four prostheses were implanted within one year and in over 50% within a five year period. Results. Taking revision of components as failure there were three infections (CLS hip, GSB and LCS knee), two aseptic loosenings (Endler cup, GSB knee), two recurrent hip dislocations, three knee bearing exchanges (LCS, INNEX), and four patella component removals (GSB, PCA). Conclusion. Quadruple arthroplasty in the lower extremity showed no increase of failure rate compared to single or dual arthroplasty patients. The results of this study support the indication for quadruple procedure with early postoperative rehabilitation and full weight bearing. Data suggest a procedure with hips before knees and at least two weeks between arthroplasty operations

Aims: This study evaluated the outcome of bilateral hip and knee arthroplasty in the same patient with special regards to schedule planning, postoperative complications and follow-up. Methods: Since 1985 more than 6000 THA and 5500 TKA were implanted in one large center, of which 8% were rheumatoid patients. Quadruple THA and TKA were performed in a total of 58 (0.1%) of which 88% were RA. Mean follow-up of knees was 8.5 years (1–17), of hips 9.5 years (1–18). On average 67% of implants were uncemented. In 21% of the cases all four prostheses were implanted within one year and over 50% within five years. Results: Taking revision of components as failure there were three infections (CLS hip, GSB and LCS knee), two aseptic loosenings (Endler cup, GSB knee), two recurrent hip dislocations, three knee bearing exchanges (LCS, INNEX), and four patella component removal (GSB, PCA). Discussion and Conclusion: Quadruple arthroplasty in the lower extremity did not show an increased failure rate compared with single arthroplasty in this center. The results of this study support the indication for quadruple procedure with early postoperative rehabilitation and full weight bearing. Data suggest a procedure with hips before knees and at least three weeks between any arthroplasty operations

Juvenile hip instability is associated with many conditions. Most of them belong to the group of neuromuscular diseases. Generally following categories can be enumerated: 1. Cerebral palsy, 2. Myelomeningocele, 3. Spinal cord injury, 4. Paraplegia following spine surgery, 5. Poliomyelitis, 6. Inflammatory hip disease, 7. Idiopathic instability, 8. Recurrent post-traumatic hip instability. In the groups 1–5 a chronic muscle imbalance is the reason of the displacement of the femoral head. Inflammatory joint disease produces displacement through cartilage and bone destruction and increased intra-articular pressure. Very rare idiopathic instability is usually associated with generalised hypermobility. For the early diagnosis a careful clinical examination is necessary involving range of motion, testing of the hip stability by the Palmén’s test in the same way like in new-borns. Routine x-ray screening at least once per year is mandatory. For the groups 1–5 a muscle imbalance has to be corrected first. Elimination of muscles contractures or muscles transfers respectively, showed a high efficiency if these surgical corrections were performed early. Femoral osteotomy alone does not provide reliable results. Any form of pelvic osteotomy is necessary to correct acetabular insufficiency. For the inflammatory hip disease early active surgical treatment is best prevention of displacement. Idiopathic hip instability has to be differentiated from common snapping hip. No treatment is necesary. Recurrent hip dislocation can be cured by a posterior capsulorrhaphy

Controversy has existed for decades over the role of fretting-corrosion in modular CoCr heads used with stems of CoCr vs Ti6Al4V. Since retrieval data on taper performance remains scant, we report here an18-year survivorship of a Ti6Al4V: CoCr combination (APR design; Intermedics Inc). Unique to this study were the threaded profiles present on both stem and head tapers (Fig. 1). This female patient was revised for pain, osteolysis and recurrent hip dislocation at 17 years, 10 months. A prior MPE hip replacement performed for her severely dysplastic right hip had lasted 11 years. At this 2nd revision, the 28 mm CoCr head was found dislocated posteriorly and superiorly. Metallosis was evident in the tissues. The polyethylene liner showed extensive rim damage on both anterior and posterior aspects. The neck of her APR Revision stem (Intermedics Inc) had worn through the polyethylene rim and impinged on the metal cage. The cage was found loose, the liner had disassociated, and the peri-trochanteric areas were compromised by massive osteolysis. The femoral stem and head were removed together without disassembly. The femoral stem and acetabular construct were replaced by an ARCOS revision system using 36 mm head with a Freedom cup (cemented to Max-Ti cage; Biomet Inc.). The complete femoral neck and head were bi-valved assembled in horizontal plane for direct imaging by interferometry and SEM (Fig. 1a). After sectioning the head separated from the stem. Quantitative imaging used 1 to 5 regions with 6-replicate measurements per region and differentiation into contact and non-contact zones (Fig. 1b). Visual corrosion mapping (3) was recorded digitally in 4 anatomical views (Figs 1b–f). The thread profile on contact zone inside the head (Fig. 2a) had a pitch of approximately 40 μm and a peak-to-valley depth of 4 μm overall (Fig. 2b profile section of thread: PV = 2 μm). The thread profile on stem trunnion (Fig. 3a) had a pitch of approximately 125 μm and a peak-to-valley depth of 3.5 μm overall (Fig. 2b profile section of thread: PV = 1 μm). Thus the stem trunnion thread was much coarser than the head. Overall corrosion grading was judged very mild. Overall we were satisfied that this Ti6Al4V: CoCr combination taper junction with threaded interfaces had performed very well for 18 years. Nevertheless, our visual grading was subject to opinion and thus unrewarding. The continuing project will quantify the contacting and non-contacting regions of head and stem (Fig. 1b)

Introduction: Revision Hip Surgery presents an increasing Orthopaedic Burden. Indications for revision include recurrent hip dislocation, infection, peri-prosthetic fracture, failure of implants, including aseptic loosening, osteolysis, wear or mechanical failure of components. Within the region of Northern Ireland, we have investigated the indications for revision hip procedures, carried out from April 2006 to March 2007. We wanted to establish if the indications of revision surgery are comparable to other national registers. Methods: An audit of all hospitals, which carry out hip revision surgery, was carried out, to identify patients who have undergone revision total hip surgery. The indications for revision procedures were identified, from hospital databases, patient records and examination of pre-operative X-rays. Revision procedures included replacement of one or both components, application of Posterior Lip Augmentation Devices and cable plating or component revision for peri-prosthetic fractures. Results: 180 patients, who had undergone revision, were identified in six hospitals. 56 were female and 124 were male. Revisions were performed for a peri-prosthetic fracture in 38 (21%), infection in 12 (7%), recurrent dislocation in 23(13%) and failure of implants in 105 (58%). In 2 patients (1%) revision was performed after the development of avascular necrosis following resurfacing hip replacement. Discussion: The largest body of information on revision hip surgery is the Swedish registry. Their incidence for revision hip surgery is 7%. Their indications were: aseptic loosening 71%, Infection 7.5%, Fracture as 5.6% and dislocation as 4.8%. Our data indicate a greater prevalence of revision for recurrent dislocation and peri-prosthetic fractures than the Swedish data. Further work should aim to identify any remediable surgical factors which account for these differences

Acetabular component malposition is the cause of half of all cases of recurrent hip dislocation. Intraoperative xrays after component insertion are helpful, yet it is certainly more useful to know the exact component position before final component insertion. The current study reviews results of acetabular component positioning using surgical navigation. A prospective study of acetabular component positioning using surgical navigation was conducted in 22 hips of 21 patients. The technique involves insertion of a dynamic reference frame onto the pelvis during the surgical exposure and the acquisition of AP fluoroscopic views of each hip. Using the Fluoronav software and the ION surgical navigation system (Medtronics, Louisville, Colorado) a virtual horizontal line was then drawn between the teardrops. Acetabular component abduction was then aimed for 41 degrees. Component abduction was measured intra-operatively during component insertion by measuring the angle between the acetabular insertion handle and the virtual horizontal line between the teardrops. Post-operative xrays were analyzed for acetabular component abduction angle. Using surgical navigation and aiming for 41 degrees of abduction resulted in post-operative cup positions averaging 40.8 degrees (range 37 to 44 degrees). These results show dramatically improved accuracy as compared to 85 acetabular component inserted without navigation showing a mean abduction of 42.8 degrees but with a range of 25 to 59 degrees. Frame placement and image acquisition required about 10 minutes. All intra-operative imaging after component insertion in complex cases was unnecessary. Having the dynamic reference frame in place also allowed assessment of pelvic position during surgery. Pelvic orientation varied greatly between patients on the operating table from about 12 degrees abducted to 12 degrees adducted. Further, pelvic orientation varied during surgery. Surgical navigation allows extremely accurate positioning of the acetabular component at the time of total hip replacement surgery with an accuracy far greater than any study of acetabular component positioning reported in the literature. The pelvis is typically not orthogonal to the operating table during total hip arthroplasty and its position varies widely between patients and in the same patient during the procedure. Since acetabular component malposition represents the cause of half of all cases of recurrent dislocation, surgical navigation has been shown to directly address and potentially eliminate the problem of acetabular component malposition

Aims

Isolated acetabular liner exchange with a highly crosslinked polyethylene (HXLPE) component is an option to address polyethylene wear and osteolysis following total hip arthroplasty (THA) in the presence of a well-fixed acetabular shell. The liner can be fixed either with the original locking mechanism or by being cemented within the acetabular component. Whether the method used for fixation of the HXLPE liner has any bearing on the long-term outcomes is still unclear.

Recurrent posterior dislocation is a recognised complication following primary total hip arthroplasty. Incidences of between 0.11% and 4.5% have been reported in the literature. Component revision is regarded as standard management of recurrent posterior dislocation. However, revision surgery is a major surgical procedure and is often unsuitable for elderly, frail patients. A congruent, ultra-high molecular weight polyethylene acetabular augment with a stainless steel backing plate has been developed. This can be inserted providing there is no malalignment, wear or loosening of the primary components. In this study we compared twenty patients who underwent conventional revision surgery to twenty patients who had a PLAD inserted for recurrent posterior dislocation following primary Charnley total hip arthroplasty. Both groups were age and sex-matched and the average number of dislocations prior to surgery was three for each group. For the PLAD group, the mean operative time, the mean intraoperative blood loss, the time spent in HDU, the transfusion requirements and the duration of hospital stay was significantly less than that for the revision group. Furthermore, there was no significant difference in the Oxford Hip Score recorded preoperatively and at 6 weeks, 6 months, one year and two years following surgery. None of the patients had sustained a further dislocation at latest review. We conclude that the Posterior Lip Augmentation Device is a safe and effective option in the management of patients with recurrent posterior hip dislocation when there is no evidence of component failure or gross malposition