Complications in primary total hip arthroplasty: avoidance and management of dislocations.
ABSTRACT Dislocation in primary total hip arthroplasty is common and problematic and is attributable to several factors, including previous hip surgery, neuromuscular disorders, cerebral dysfunction, psychosis, alcoholism, and female gender. Factors under the control of the surgeon include component orientation and restoration of soft-tissue tension. Prosthetic factors lowering the risk of dislocation include increasing the size of the prosthetic femoral head, keeping femoral neck circumference to a minimum, and optimizing the geometry of the acetabular component. Postoperatively, patients should be expected to comply with standard hip precautions. Treatment is with immediate closed reduction. Multiple dislocations can be treated by advancing the trochanter in the presence of inadequate soft-tissue tension, revision arthroplasty in the presence of malpositioned components, or the use of a constrained cup when intraoperative instability persists. Because the risk of redislocation is much higher than that for first-time dislocation, prevention is critical. An enhanced repair technique can be used to reconstruct the posterior soft-tissue sleeve during the posterior surgical approach. This technique has been successful in lowering the dislocation rate from 4% to 0% in a series of 395 consecutive patients.
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ABSTRACT: We identified and compared the impingent-free range of motion (ROM) and subluxation potential for native hip, femoral head resurfacing (FHR), and total hip arthroplasty (THA). These constructs were also compared both with and without soft tissue to elucidate the role of the soft tissue. Five fresh-frozen bilateral hip specimens were mounted to a six-degree of freedom robotic manipulator. Under load-control parameters, in vivo mechanics were recreated to evaluate impingement free ROM, and the subluxation potential in two "at risk" positions for native hip, FHR, and THA. Impingement-free ROM of the skeletonized THA was greater than FHR for the anterior subluxation position. For skeletonized posterior subluxations, stability for THA and FHR constructs were similar, while a different pattern was observed for specimens with soft tissues intact. FHR constructs were more stable than THA constructs for both anterior and posterior subluxations. When the femoral neck is intact the joint has an earlier impingement profile placing the hip at risk for subluxation. However, FHR design was shown to be more stable than THA only when soft tissues were intact. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.Journal of Orthopaedic Research 03/2013; · 2.88 Impact Factor
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ABSTRACT: We report how changes to our total hip arthroplasty (THA) surgical practise lead to a decrease in early hip dislocation rates. Group B consisted of 421 consecutive primary THA operations performed via a posterior approach. The operative technique included a meticulous repair of the posterior capsule, alignment of the acetabular cup with the transverse acetabular ligament (TAL) and a 36-mm-diameter femoral head. We compared the dislocation rates and cost implications of this technique to a historical control Group A consisting of 389 patients. The control group had their THA performed with no repair of the capsule, no identification of the TAL and all received a 28-mm-diameter head. Our primary outcome is the rate of early hip dislocation and we hypothesised that we can reduce the rate of early hip dislocation with this new regime. In Group B there were no early dislocations (within 6 months) and two (0.5 %) dislocations within 18 months; minimum follow-up time was 18 months with a range of (18-96 months). This compared to a 1.8 % early dislocation rate and a 2.6 % rate at 18 months in Group A; minimum follow-up time was 60 months with a range of (60-112 months). These results were statistically significant (p = 0.006). We suggest that when primary hip arthroplasty is performed through a posterior approach, a low early dislocation rate can be achieved using the described methods.Archives of Orthopaedic and Trauma Surgery 03/2012; 132(7):1031-6. · 1.36 Impact Factor
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ABSTRACT: Luxation following endoprosthetic hip replacement represents a frequent and severe complication and is the reason for a relevant number of hip arthroplasty revision interventions. The probability of occurrence of luxation of a total hip arthroplasty is associated with the indications, patient and operation-specific risk factors. Approximately 50 % of luxations after total hip arthroplasty occur within 3 months of the operation (early luxation). The diagnostics of luxation of total hip arthroplasty are carried out by clinical and radiological methods. The causative assignment is made by assessment of joint stability, the bony situation (e.g. loosening, periprosthetic fracture and defects) and the soft tissue (e.g. pelvitrochanterian musculature). In cases of clinical and paraclinical signs of infection and of late luxations, a joint puncture is indicated. Therapy decisions are made depending on the cause (e.g. implant malpositioning, pelvitrochanterian insufficiency, impingement, incongruence between head and inlay and combinations of causes). Therapy of acute total hip prosthesis luxation begins with imaging controlled repositioning carried out with the patient under adequate analgesia and sedation. Conservative therapy is carried out by immobilization with a hip joint orthesis or pelvis-leg cast for 6 weeks. Operative therapy strategies for recurrent luxation are restoration of the correct implant position and sufficient soft tissue tension. Larger hip heads, bipolar heads and tripolar cups are more commonly used due to the geometrically lower probability of dislocation (higher jumping distance). Luxation of total hip prostheses due to infection is treated according to the principles of periprosthetic infection therapy. The rate of recurrence of luxation of 30 % is high so that in cases of unsuccessful therapy treatment should best be carried out in a center for revision arthroplasty. The search for the exact cause of total hip prosthesis luxation is extremely important. A classification is only possible when the exact cause is known and together with patient and implant-specific details the therapeutic approach can be ascertained. In revision operations the intraoperative functional diagnostics must be exactly documented. The reasons for delayed luxations could be prosthesis infections, abrasion and loosening.Der Orthopäde 01/2014; · 0.51 Impact Factor