Undergoing Revision Total Knee Arthroplasty Research Articles

Extensile Exposure in Revision Total Knee Arthroplasty Using an Osteomyofascial Flap

Adequate exposure is essential for a successful revision total knee arthroplasty. A technique of approach by developing an osteomyofascial flap over the tibial tubercle is introduced in this article. Between September 1998 and August 2000, this technique was applied to assist in the surgical exposure of the knee in 22 patients undergoing revision total knee arthroplasty. When this procedure is performed, a thin bony flap is developed over the tibial tubercle and upper tibia. The overlying soft tissue including fascia, muscle, and periosteum is not disturbed during this procedure. Simple sutures were used to reattach the flap, and no special devices such as screws or wires are needed. The postoperative rehabilitation program is the same as that undertaken in primary cases. At the average follow-up time of 49 months, 21 patients have satisfactory results. This technique has the merits of its simplicity: there is no need to use a special device to fix the flap when closing the wound, the continuity of the extensor mechanism is maintained, and the normal postoperative rehabilitation program is not disturbed. Good clinical results could always be anticipated by using this technique when it is performed carefully.

Unicompartmental knee arthroplasty in patients sixty years of age or younger.

Unicompartmental knee arthroplasty has been used to treat elderly, low-demand patients, but the literature is sparse regarding the use of this procedure for younger, active patients. The purpose of the present retrospective study was to evaluate the results of unicompartmental knee arthroplasty in younger, more active patients. Forty-one patients underwent forty-six consecutive unicompartmental knee arthroplasties with use of the Miller-Galante system between 1988 and 1996. All of the patients were sixty years of age or younger and all were physically active. The Hospital for Special Surgery knee score and the University of California at Los Angeles activity assessment were used to rate the function and to determine the activity level of each patient, respectively. Serial radiographs were used to evaluate the status of prosthetic fixation, femorotibial alignment, and the progression of arthrosis in the unreplaced compartment. Long-term survivorship was calculated with use of Kaplan-Meier analysis. The mean duration of follow-up was eleven years. Of the forty-five knees that were available for follow-up, three had been revised. The Hospital for Special Surgery score was excellent for thirty-nine (93%) of the remaining forty-two knees and good for three. The University of California at Los Angeles activity assessment score was 6.6 +/- 1.4 for the knees in which the original prosthesis had been retained and 7.3 +/- 1.5 for those in which it had been revised. Two asymptomatic patients had revision of a modular tibial component because of substantial radiographic evidence of polyethylene wear; one of these patients had exchange of the polyethylene insert and the tibial tray, and the other had exchange of the polyethylene insert only. A third patient underwent revision total knee arthroplasty because of continuing knee pain and a progressive tibial radiolucent line that was >2 mm in width. The average postoperative femorotibial alignment was 5 degrees of valgus. Nine knees had progression of arthritis in the unresurfaced compartment; none of these knees were revised, and none of the patients had deterioration in the Hospital for Special Surgery score. Kaplan-Meier analysis demonstrated an eleven-year survivorship of 92%. At an average duration of follow-up of eleven years, unicompartmental knee arthroplasty was associated with pain relief and excellent function in a cohort of patients who had been sixty years of age or younger and active at the time of surgery.

“Wandering resident” surgical exposure for 1- or 2-stage revision arthroplasty in stiff aseptic and septic knee arthroplasty

A retrospective study was performed on 18 patients who had undergone revision total knee arthroplasty (TKA) between 1992 and 2000 with stiff knee (average, 50° range of motion). The so-called “wandering resident” surgical exposure was used. This procedure was used twice in 5 cases with low-grade infection in a 2-stage revision of their septic prosthesis. Follow-up was from 1 to 8 years (average, 3.5 years). All patients had good clinical results, with an 86° average range of motion. The Knee Society Score preoperatively ranged from 35 to 52 (average, 40) and improved to 72 to 89 (average, 84). Postoperative rehabilitation was slower, requiring the use of a knee brace in extension for 6 weeks for support while the patient ambulated and without this support for daily physiotherapy and continuous passive motion at 0° to 70°. Full range of motion with no brace was started after 6 weeks.

Revision and salvage patellar arthroplasty using a porous tantalum implant

The purpose of this study was to assess the clinical results of a new surgical technique and novel porous tantalum implant for augmentation or arthroplasty of the patella for 11 patients who underwent revision total knee arthroplasty. Preoperative average knee function and pain scores were 24 and 20, respectively, and average range of motion (ROM) was 62°. The low knee scores reflect the immobility, trauma, and/or pain associated with the patients’ presenting conditions. At the most recent follow-up (average, 32 months), the average knee function and pain scores were 69 and 53, respectively, and the average ROM was 103°. Radiographically, all implants were stable, and patient satisfaction has been excellent. These results indicate that this surgical technique and porous tantalum prosthesis can substantially improve function and reduce pain for patients with severe patellar bone loss and other complicating factors.

Infection after total knee arthroplasty.

The aim of our study was to determine the current incidence and outcome of infected total knee arthroplasty (TKA) in our unit comparing them with our earlier audit in 1986, which had revealed infection rates of 4.4% after 471 primary TKAs and 15% after 23 revision TKAs at a mean follow-up of 2.8 years. In the interim we introduced stringent antibiotic prophylaxis, and the routine use of occlusive clothing within vertical laminar flow theatres and 0.05% chlorhexidine lavage during arthroplasty surgery. We followed up 931 primary TKAs and 69 revision TKAs for a mean of 6.5 years (5 to 8). Patients were traced by postal questionnaire, telephone interview or examination of case notes of the deceased. Nine (1%) of the patients who underwent primary TKA, and four (5.8%) of those who underwent revision TKA developed deep infection. Two of nine patients (22.2%) who developed infection after primary TKA were successfully treated without further surgery. All four of the patients who had infection after revision TKA had a poor outcome with one amputation, one chronic discharging sinus and two arthrodeses. Patients who underwent an arthrodesis had comparable Oxford knee scores to those who underwent a two-stage revision. Although infection rates have declined with the introduction of prophylactic measures, and more patients are undergoing TKA, the outcome of infected TKA has improved very little.

Screening for symptomatic metal sensitivity: a prospective study of 92 patients undergoing total knee arthroplasty

Metal sensitivity (MS) reactions to implant metals represent a rare but well-documented complication following total joint arthroplasty (TJA). Although 20–25% of post-TJA patients develop MS, only a few highly susceptible patients (<1%) exhibit symptoms. Whether surgeons should perform screening for MS is currently a matter of debate. The present study investigated the clinical importance of screening for patients predisposed to symptomatic MS, and the specific metals causing symptomatic MS following total knee arthroplasty (TKA). Between 2000 and 2002, a total of 108 primary TKAs were performed on 92 patients. Preoperatively, all patients underwent modified lymphocyte stimulation test (mLST) to Ni, Co, Cr, and Fe. Of the 92 patients, 24 (26%) displayed positive preoperative responses to at least one metal. Five patients displayed implant metal-related eczema and were all mLST-positive preoperatively, suggesting that screening for symptomatic MS is clinically useful. Two of these underwent revision TKA and thereafter, eczema healed and mLST results changed from positive to negative. All mLST-positive patients were divided into three groups: Group I, patients with eczema; Group II, patients with clear history of MS; and Group III, patients neither eczema nor history of MS. When the type of sensitive metals were compared among the three groups, a significant association between presence of Cr-sensitivity and development of eczema ( P<0.05) was identified. No significant association was observed between other metals and development of eczema or history of MS. This indicates that Cr is a potential candidate metal for causing eczema in our TKA series, and Cr-sensitivity may offer a potential predictor for symptomatic MS. The present study indicates that the surgeons should undertake routine preoperative screening for MS, particularly to Cr.

Screening for symptomatic metal sensitivity: a prospective study of 92 patients undergoing total knee arthroplasty

Metal sensitivity (MS) reactions to implant metals represent a rare but well-documented complication following total joint arthroplasty (TJA). Although 20–25% of post-TJA patients develop MS, only a few highly susceptible patients (<1%) exhibit symptoms. Whether surgeons should perform screening for MS is currently a matter of debate. The present study investigated the clinical importance of screening for patients predisposed to symptomatic MS, and the specific metals causing symptomatic MS following total knee arthroplasty (TKA). Between 2000 and 2002, a total of 108 primary TKAs were performed on 92 patients. Preoperatively, all patients underwent modified lymphocyte stimulation test (mLST) to Ni, Co, Cr, and Fe. Of the 92 patients, 24 (26%) displayed positive preoperative responses to at least one metal. Five patients displayed implant metal-related eczema and were all mLST-positive preoperatively, suggesting that screening for symptomatic MS is clinically useful. Two of these underwent revision TKA and thereafter, eczema healed and mLST results changed from positive to negative. All mLST-positive patients were divided into three groups: Group I, patients with eczema; Group II, patients with clear history of MS; and Group III, patients neither eczema nor history of MS. When the type of sensitive metals were compared among the three groups, a significant association between presence of Cr-sensitivity and development of eczema (P<0.05) was identified. No significant association was observed between other metals and development of eczema or history of MS. This indicates that Cr is a potential candidate metal for causing eczema in our TKA series, and Cr-sensitivity may offer a potential predictor for symptomatic MS. The present study indicates that the surgeons should undertake routine preoperative screening for MS, particularly to Cr.

The results of tibial tubercle osteotomy for revision total knee arthroplasty

Tibial tubercle osteotomy was used in the surgical exposure of 67 knees in 64 patients undergoing revision total knee arthroplasty. The clinical and radiographic results were reviewed retrospectively. The mean follow-up time was 30 months (range, 5–60 months). Knee Society scores (KSS) confirmed good or excellent results in 87% of the knees, and the mean KSS was 86. The procedure was particularly effective in 2-stage exchanges for infected total knee arthroplasty, in which infection was eradicated in 9 of 10 cases, with a mean KSS of 82. In this series, no patellofemoral complications, no component malalignments, and no avulsions of the patellar tendon occurred. Serious complications directly related to the tibial tubercle osteotomy occurred in 5 patients (7%).

Use of a trabecular metal patella for marked patella bone loss during revision total knee arthroplasty

This study evaluates the short-term results following patellar resurfacing with a trabecular metal patella shell in the setting of marked patellar bone loss at the time of revision total knee arthroplasty (TKA). Twenty consecutive patients undergoing revision TKA with the use of a trabecular metal patella were evaluated at a mean 23-month follow-up. All patients had marked patellar bone loss at surgery precluding resurfacing with a standard cemented patellar button. Results were good or excellent in 17 of 20 patients. There were no displacements of any trabecular metal patella shells, and the fixation appeared excellent despite the poor quality of bone remaining. Complications included 3 patients with polar patella fractures postoperatively. Qualitatively, these results compare favorably with patellar resection arthroplasty in this setting.

In Vivo Deterioration of Tibial Baseplate Locking Mechanisms in Contemporary Modular Total Knee Components

The results of recent studies documenting the backside wear of polyethylene inserts retrieved from total knee implants call into question the stability of the locking mechanisms of modular tibial components. Wear of the metal tibial baseplate suggests that the capture mechanisms of some modular fixed-bearing tibial components do not adequately restrict in vivo motion of the insert. The purposes of this study were (1) to present a method for evaluating locking-mechanism stability and (2) to investigate the stability of modular tibial components after an interval in vivo. We measured the anteroposterior and mediolateral motion between the polyethylene insert and the tibial tray in a variety of modular total knee tibial components. A uniaxial mechanical testing machine was used to evaluate the stability of ten unimplanted components (control group), fifteen implants obtained from patients who were undergoing revision total knee arthroplasty (revision group), and fifteen devices retrieved post mortem (autopsy group). We applied loads along the anteroposterior and mediolateral axes of the tibial component and recorded the maximum insert displacement that occurred. From this value, we calculated an insert-motion index, the magnitude of a two-dimensional vector that represented the total motion in the transverse plane. For the control group, the mean insert-motion index was 64 +/- 13 microm (range, 6 to 157 microm); for the revision group, it was 341 +/- 51 microm (range, 104 to 718 microm); and for the autopsy group, it was 380 +/- 45 microm (range, 122 to 657 microm). The insert-motion index for the control group was significantly lower than that for the revision group (p = 0.001) or autopsy group (p < 0.001). Motion between the polyethylene insert and the metal baseplate in contemporary modular tibial designs increases after a period of in vivo loading. Although there are several advantages to the use of modular tibial components, these advantages must be weighed against the disadvantage of backside wear debris secondary to motion of the modular insert. Debris from backside wear combined with wear from the articular side might account for the increasing prevalence of osteolysis since modular components have become widely used.

Morselized bone grafting of defects in revision total knee arthroplasty.

In a prospective, multicenter study evaluating one revision knee system, 33 of 409 patients underwent morselized bone grafting for tibial and femoral defects. Fifty-four percent of defects were bicondylar and the defect volumes averaged 36 cc3. There was no difference in preoperative or postoperative knee scores between patients undergoing morselized grafting and the entire group. Radiographic evaluation showed remodeling of the grafted areas consistent with viable incorporation of the graft. The incidence of radiolucent lines, at 2 years followup, was not different between the patients who received grafting and the patients who did not receive grafting. There have been no clinical failures or reoperations in the patients who received morselized bone grafting. Morselized bone grafting seems to offer a viable alternative in the reconstruction of osseous defects in patients undergoing revision total knee arthroplasty.

Bone-grafting for severe patellar bone loss during revision knee arthroplasty.

Severe patellar bone loss may preclude adequate fixation of another patellar prosthesis as a part of revision knee replacement. The purpose of this study was to describe the surgical technique and early clinical results of an alternative to the conventional treatment options of either patellectomy or retention of the remaining patellar osseous shell. The goals of this procedure are to restore patellar bone stock and potentially to improve the functional outcome. Severe patellar bone loss had left a "patellar shell" that precluded insertion of another patellar implant in nine of 100 consecutive knees undergoing revision total knee arthroplasty. Rather than performing a patellectomy or simply retaining the patellar osseous shell in these nine knees (eight patients), I performed a surgical procedure in which a tissue flap was secured to the patellar rim to contain cancellous bone graft inserted into the patellar bone defect. Final follow-up was at a mean of 36.7 months (range, twenty-four to fifty-five months) after the patellar bone-grafting procedure. The mean preoperative Knee Society scores for function and pain were 39 points (range, 18 to 82 points) and 40 points (range, 20 to 80 points), respectively. At the time of final follow-up, the Knee Society function and pain scores had improved significantly, to a mean function score of 91 points (range, 80 to 98 points) and a mean pain score of 84 points (range, 65 to 100 points) (p<0.05). The point of greatest patellar thickness measured intraoperatively ranged from 7 to 9 mm. Patellar thickness on immediate postoperative Merchant radiographs averaged 22 mm (range, 20 to 25 mm) whereas, at the time of final follow-up, patellar thickness averaged 19.7 mm (range, 17 to 22.5 mm). In contrast with other treatment alternatives, this surgical procedure imparts the potential for restoring patellar bone stock and may improve functional outcome by facilitating patellar tracking and improving quadriceps leverage. On the basis of satisfactory short-term to mid-term clinical results, this technique of patellar bone-grafting appears to be an important addition to the armamentarium of surgeons performing revision knee arthroplasties.

The use of a modular rotating hinge component in salvage revision total knee arthroplasty

Revision total knee arthroplasty (TKA) using a second-generation modular rotating hinge design was performed on 16 knees in 15 patients over a 5-year period. Follow-up of 2 to 6 years (mean, 51 months) was obtained in 14 knees in 13 patients. Indications for revision were aseptic loosening of a hinged prosthesis (8 knees), loosening and bone loss associated with chronic extensor mechanism disruption (2 knees), component instability with chronic medial collateral ligament disruption (3 knees), and comminuted distal femur fracture (1 knee). Clinical and radiographic results were reviewed and compared with 87 patients who underwent revision TKA using a standard condylar revision design during the same period. Early results showed comparable postoperative knee scores and range of motion between the 2 groups despite the use of the rotating hinge component in more complex revision cases. No patient has exhibited radiographic evidence of definite component loosening. Alignment of 5° to 10° of valgus in the frontal plane and within 2° of neutral in the sagittal plane was achieved consistently. Short-term clinical and radiographic results are encouraging and suggest that a second-generation modular rotating hinge component can be used successfully in selected salvage revision cases.

Pain at the End of the Stem After Revision Total Knee Arthroplasty

A consecutive series of patients undergoing revision total knee arthroplasty was studied prospectively. Clinical and radiographic assessment was performed preoperatively, 6 and 12 months postoperatively, and annually thereafter. Evaluation consisted of a Knee Society clinical score and assessment of patient satisfaction. In addition, patients completed drawings of their lower extremity regarding the location and severity of the pain they experienced preoperatively and at minimum 2-year followup (mean, 36 months; range, 24-48 months). Pain that was localized to the diaphyseal region of the femur or tibia on the drawing was defined as pain at the end of the stem. Clinical, radiographic, and pain drawing data were completed for patients who had 66 of 78 revision total knee arthroplasties performed during the time of the study (85%). All procedures were performed with the same implant system and instrumentation and included fluted cobalt-chrome stems for all patients in whom the stem was implanted without cement and slightly underreamed (press fit). All femoral components had the surface cemented with the stems press fit. Sixteen of the tibial stems were cemented fully, whereas the remaining 50 tibial components were cemented on the surface only with the stems press fit. Localized pain at the end of the stem was present on the femoral side in seven of 66 patients (11%) and in seven of 50 patients with press fit tibial stems (14%). Patients with pain at the end of the stem at 2 to 4 years postoperatively had significantly lower preoperative function scores and overall Knee Society clinical score. Postoperatively, patients with pain at the end of the stem had a significantly lower clinical score; however the postoperative function score and Knee Society clinical score were not significantly different than scores of patients who did not have pain at the end of the stem. There was no correlation between the stem diameter and the occurrence of pain; however, there was a trend for percent canal fill to be higher on the tibial side in patients with pain (71% versus 63%), but this was not statistically significant. Three of the 16 patients with cemented tibial stems (19%) experienced pain at the end of the stem. Patients with press fit stems who had pain at the end of the stem were more likely to express dissatisfaction with the surgical procedure than patients without pain at the end of the stem.

Clinical outcome of revision of the patellar component in total knee arthroplasty. A 2- to 7-year follow-up study

The objectives of this study were to determine the relationship between the thickness of the residual patellar bone and the composite patella-patellar component, and the clinical outcome in patients who had undergone revision total knee arthroplasty (TKA) with a biconvex patellar component. Clinical outcome after at least a 2-year follow-up was determined using the Knee Society pain and functional scores, and radiographically, with the thicknesses of the patellar bone and composite measured in 23 knees (22 patients). The thickness of the patellar bone after preparation for a biconvex patellar component was significantly less for revised patellae (average, 5.0mm) than the primary patellae (average, 7.9mm; P < 0.01). Differences in thickness between preoperative patellae, primary composites, and revision composites did not significantly affect postoperative results. There were no patellar fractures, despite the relatively thin bone remnant in the revision patients. Radiolucency was observed in 8% of the revisions. A patella with a thickness of residual bone of as little as 5mm can provide favorable clinical results in revision TKA with restoration of the composite thickness of the patella achieved using a thick but small-diameter biconvex patellar component.

Endosteal referencing in revision total knee arthroplasty

A method of orienting the femoral and tibial bone cuts relative to the endosteal cortex of the femur and tibia was used in 32 patients who underwent revision total knee arthroplasty. The mean orientation of the femoral component was 96.74° ± 1.03°, mean orientation of the tibial baseplate was 90.71° ± 1.10°, mean anatomic tibiofemoral alignment was 7.42° ± 1.69° of valgus, and mean mechanical tibiofemoral alignment was 1.09° ± 1.83° of valgus. Mean tibial bowing was 1.63° ± 1.57° of valgus, and mean femoral bowing was 0.58° ± 1.53° of varus. Valgus tibial bowing was correlated with valgus orientation of the tibial component ( r = .86, P < .000001), and varus femoral bowing was correlated with orientation of the femoral component ( r = .54, P = .0054). Referencing the implant position from the endosteal cortex of the intramedullary canals provides a reliable method of achieving satisfactory alignment in most revision total knee arthroplasties; however, bowing of the femur or tibia can affect alignment.

Blood transfusion strategies for total knee arthroplasty: Minimizing autologous blood wastage, risk of homologous blood transfusion, and transfusion cost

In this nonrandomized study, alternative strategies were suggested to 10 orthopaedic surgeons to minimize autologous blood wastage, the risk of homologous blood transfusion, and cost associated with blood product usage after total knee arthroplasty (TKA). One hundred fifty-five patients with 177 consecutive TKAs over a 2-year period were studied. Group 1 patients had undergone unilateral TKA and did not predonate; 1A patients (n = 19) were drained with a Hemovac, and 1B patients (n = 28) with a postoperative blood recovery system. Group 2 patients (n = 47) predonated one packed red blood cell (pRBC) unit. Group 3 patients (n = 20) predonated 2 pRBC units. Group 4 patients had undergone bilateral sequential TKAs (n = 21) and had predonated 2 pRBC units. Group 5 patients (n = 14) had undergone revision TKA procedures and their blood requirements were individualized. Group 6 patients (n = 6) had preexisting anemia and were excluded from the study. There was no significant difference in total blood loss (909 mL) between groups. Female sex was associated with significantly lower admission hematocrit. Homologous blood was required for 4% of patients in the entire study and the percentage was not statistically different between groups. Twenty-five percent of patients who predonated autologous pRBCs did not use all or some of it. In group 1, the postoperative blood recovery system had a significant effect on reducing postoperative hematocrit drop ( P = .0001), but it was not a significant factor if autologous pRBCs were available. The costs associated with group 1A were significantly less ( P = .0001) compared with the other groups; group 1A had the highest admission hematocrit (43.2). Transfusion with autologous pRBCs was related to lower admission hematocrit rather than to increased postoperative blood loss. An algorithm is presented to provide cost-effective management of blood products after TKA.

Distal Realignment of the Patellar Tendon to Correct Abnormal Patellar Tracking

Between January 1980 and January 1994, 31 knees required distal realignment of the extensor mechanism to treat lateral patellar subluxation that could not be corrected with lateral patellar release and vastus medialis advancement during total knee arthroplasty. Fifteen had a preoperative valgus angle of more than 12 degrees, and 16 were undergoing revision total knee arthroplasty. Ten knees had a modified Roux-Goldthwait procedure, 18 had medial tibial tubercle transfer, and three had medial transfer of the medial 1/2 of the patellar tendon. The length of followup ranged from 2 to 16 years. No late patellar subluxations or dislocations have occurred in any of these cases. Three cases of medial tibial tubercle transfer had hematomas develop, with two requiring surgical evacuation; one of these developed a late infection. No fractures or displacements of the tubercle fragment have occurred. No significant patellar complications have occurred in those patients who underwent the modified Roux-Goldthwait procedure or the medial transfer of the medial 1/2 of the patellar tendon. One year after surgery, the mean knee flexion was 113 degrees, four knees had a flexion contracture of 5 degrees, and none had a quadriceps lag.

Use of allograft bone in revision total knee arthroplasty in previously septic knees: short-term results

Allograft bone was used in eight patients to reconstruct tibial and femoral bone deficiencies in revision total knee arthroplasty of previously septic knees. At a mean of 30.1 months after revision, none had recurrence of sepsis. One patient required resection arthroplasty three weeks postoperatively because of skin flap necrosis. These results suggest that allografts of bone are useful in reconstructing bone deficiencies in carefully selected individuals undergoing revision total knee arthroplasty with a history of sepsis of the knee. Early recurrence of infection was not found. The long-term results of using allografts in revision total knee arthroplasty in a previously septic joint remain unknown.

Revision total knee arthroplasty: Comparison of outcome following primary proximal tibial osteotomy or unicompartmental arthroplasty

Forty-three patients who had undergone revision total knee arthroplasty following either primary, medial unicondylar arthroplasty (23 patients) or valgus tibial osteotomy (20 patients) for medial compartment osteoarthritis were reviewed. Although the two groups had similar knee scores and range of motion at review, six patients (30%) who had undergone prior tibial osteotomy suffered serious postoperative complications. Of these, four patients had a deep infection. It was felt that several factors were responsible, resulting largely from difficulties in gaining access to the lateral tibial plateau and subsequently causing impairment of wound vascularity and healing. In contrast, those patients undergoing revision of unicondylar prostheses did not experience wound healing problems, but it was noted that in half of the cases, there was significant bone loss from the medial tibial plateau.