Dislocation following primary posterior-stabilized total knee arthroplasty

From 1981 through 1991, 3, 032 primary total knee arthroplasties were performed using the Insall-Burstein Posterior Stabilized Condylar Prosthesis (IB-I, IB-II, and IB-II modified) (Zimmer, Warsaw, IN). Fifteen posterior dislocations occurred: 4 with the IB-I system occurring 2 or more years after surgery, 10 with the IB-II system (8 occurring 6 months after surgery and 2 occurring 2–3 years after surgery), and 1 with the IB-II modified system occurring 9 months after surgery. Statistically significant differences for the rate of dislocation between both the IB-I and IB-II modified arthroplasties versus the IB-II arthroplasties were found (P < .001). In an attempt to identify a cause for these dislocations, the authors retrospectively assessed the 15 dislocated cases with respect to sex, age, weight, height, preoperative and postoperative Hospital for Special Surgery scores, preoperative and postoperative alignment, preoperative versus postoperative reconstruction dimensions, patellar thickness and height, and postoperative flexion and compared the results with those patients who did not experience dislocation. Possible etiologies and mechanisms of dislocation were sought. There were no significant differences between the control and study groups for any variable assessed, with the exception of postoperative flexion, which averaged 118° for the study group and 105° for the control group (P < .001). Conservative management was successful in 11 cases. In September 1988 the IB-II system was introduced; modification of the tibial insert was made in January 1990. The 10 IB-II dislocations occurred prior to the modification of the modular tibial polyethylene insert, and the 3 recurrent dislocations in this group were successfully treated with revision to this modified insert. Since this modification, 656 IB-II modified systems have been implanted with one dislocation (0.15%).     

Dislocation following total hip arthroplasty

Summary The rate of postoperative dislocation after Stanmore total hip arthroplasty in 427 cases was 4.9%; 1.4% were classified as recurrent cases. Retroversion of the acetabular component and postoperative joint laxity were the only factors that were found to predispose to dislocation. The importance of preserving the effective femoral neck length during total hip arthroplasty is emphasized.

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Zusammenfassung Die postoperative Luxationsrate nach Implantation einer Stanmore-Hüftgelenk-Totalprothese betrug in 427 Fällen 4,9%, wovon 1,4% wiederkehrende Luxationen darstellten. Eine Retroversion der Prothesenpfanne and eine postoperative Weichteillaxität im Hüftgelenkbereich waren die einzigen Faktoren, die als pradisponierend für eine Luxation ermittelt wurden. Auf die Bedeutung der Erhaltung der effektiven Schenkelhalslänge bei der Implantation einer Totalprothese wird besonders hingewiesen.

     

Dislocation following total hip arthroplasty

The rate of postoperative dislocation after Stanmore total hip arthroplasty in 427 cases was 4.9%; 1.4% were classified as recurrent cases. Retroversion of the acetabular component and postoperative joint laxity were the only factors that were found to predispose to dislocation. The importance of preserving the effective femoral neck length during total hip arthroplasty is emphasized.     

Dislocation following total knee arthroplasty: A report of six cases

Background:

Dislocation following total knee arthroplasty (TKA) is the worst form of instability. The incidence is from 0.15 to 0.5%. We report six cases of TKA dislocation and analyze the patterns of dislocation and the factors related to each of them.

Materials and Methods:

Six patients with dislocation of knee following TKA are reported. The causes for the dislocations were an imbalance of the flexion gap (n=4), an inadequate selection of implants (n=1), malrotation of components (n=1) leading to incompetence of the extensor mechanism, or rupture of the medial collateral ligament (MCC). The patients presented complained of pain, giving way episodes, joint effusion and difficulty in climbing stairs. Five patients suffered posterior dislocation while one anterior dislocation. An urgent closed reduction of dislocation was performed under general anaesthesia in all patients. All patients were operated for residual instability by revision arthroplasty after a period of conservative treatment.

Results:

One patient had deep infection and knee was arthrodesed. Two patients have a minimal residual lag for active extension, including a patient with a previous patellectomy. Result was considered excellent or good in four cases and fair in one, without residual instability. Five out of six patients in our series had a cruciate retaining (CR) TKA designs: four were revised to a posterior stabilized (PS) TKA and one to a rotating hinge design because of the presence of a ruptured MCL.

Conclusion:

Further episodes of dislocation or instability will be prevented by identifying and treating major causes of instability. The increase in the level of constraint and correction of previous technical mistakes is mandatory.     

Dislocation following revision total hip arthroplasty

Dislocation is a relatively common complication following revision total hip arthroplasty. Risk factors include surgical approach, gender, underlying diagnosis, comorbidities, surgical experience, and previous surgery; for later dislocations, risk factors include wear/deformation of polyethylene, trauma, and decreased muscle strength. Prevention and precaution are the watchwords for dislocations following revision total hip arthroplasty. For dislocations that do occur, treatment rests first on identifying the source of instability. Most dislocations can be managed by closed reduction. Constrained components may increase success rates, but only for appropriate indications. Prevention and treatment of dislocations following revision total hip arthroplasty are discussed in this article.     

Dislocation of Insall-Burstein II modified total knee arthroplasty

Dislocation of total knee arthroplasty is a rare but serious complication. The experience with the Insall-Burstein II modified knee prosthesis, which was designed to address the issue of dislocation, has been favorable. We present a series of 3 dislocations in 1,500 total knee arthroplasties done with this prosthesis, accounting for about 0.2% of cases.     

Arthroscopy following total knee arthroplasty

Conservative treatment had previously been used in our institution to treat the painful stiff knee joint following total knee arthroplasty (TKA). However, the result was not satisfactory. Arthroscopic surgery was then performed in 11 patients with painful knee joints with limited motion who had previously undergone TKA. Good results were achieved in eight patients. An average improvement of 56.3 degrees was achieved for knee range of motion. Flexion improved up to 90 degrees in all patients in the early postoperative period following arthroscopy. However, the benefits declined with time. To avoid the potential complications of manipulation and open arthrotomy, arthroscopic surgery is an option for treating the painful stiff knee joint.