Clinical comparison of the Miller Galante I and AMK total knee systems

Modified V-Y Turndown Flap Augmentation for Quadriceps Tendon Rupture Following Total Knee Arthroplasty: A Retrospective Study

BACKGROUND

Quadriceps tendon rupture following total knee arthroplasty (TKA) is an infrequent but potentially devastating adverse event. Although uncommon, the long-term sequelae of this injury can result in permanent inability to walk. Despite the severity of this injury, there is no single accepted treatment, with various surgical methods producing mixed results. Therefore, the purpose of this study was to assess the efficacy of a modified V-Y turndown flap as a viable alternative method of treatment for this injury.

METHODS

Twenty-four quadriceps tendon ruptures in 23 patients (10 men and 13 women) who underwent TKA (8 primary and 15 revision), including 1 tendon rerupture, were treated with use of a modified V-Y turndown. The average patient age at the time of the V-Y flap repair was 61 years (range, 41 to 86 years). Knee Society scores, range of motion, strength, medical comorbidities, nature of the procedure (i.e., primary versus revision), and the ability to walk were all recorded before and after the quadriceps reconstruction, along with general satisfaction and adverse events following the procedure.

RESULTS

Twelve patients (52%) had predisposing comorbidities, including obesity, diabetes, chronic dialysis, and steroid dependence. Prior to repair with the V-Y flap, none of the patients were able to walk independently, requiring either a wheelchair or walker. No patient had quadriceps strength greater than 3 (of 5), although all had full passive extension. Following the repair procedure, patients had significant (p < 0.0001) improvements in mean Knee Society knee score (88.7; range, 45 to 95) and mean strength (4.8; range, 3 to 5), and all were able to walk without assistive devices. Twenty knees exhibited active range of motion of 0° to 120°, whereas 4 had residual extensor lag of ≥5° (range, 5° to 35°). Major adverse events were limited to a single hematoma and an unacceptable extensor lag (35°) after repair.

CONCLUSIONS

The modified V-Y quadriceps tendon turndown flap was a reliable alternative treatment for achieving restoration of the extensor mechanism after complete quadriceps tendon rupture following TKA.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Implant survivorship and complication rates after total knee arthroplasty with a third-generation cemented system: 5 to 8 years followup

We evaluated implant survivorship, reoperation rates, and complication rates of a group of patients who had total knee arthroplasty with a third-generation cemented prosthetic device using cruciate-retaining and posterior-stabilized designs at 5 to 8 years followup. Three hundred thirty-four consecutive primary total knee arthroplasties (186 cruciate retaining and 148 posterior stabilized) were done in 287 patients at our institution during a 2-year period. Kaplan Meier survivorship using revision for any reason and revision for aseptic loosening as endpoints were 95.9% and 99.5% respectively at 8 years. Nine patients (four with cruciate-retaining total knee arthroplasties, five with posterior-stabilized total knee arthroplasties; 3.1%) had reoperations for any reason. No patients had reoperation for problems related to the patellofemoral joint. Thirty-two patients (11.1%) had intraoperative or postoperative complications. There were no differences in any of the outcomes analyzed between patients who had cruciate-retaining or posterior-stabilized total knee replacements. Our results show that with appropriate patient selection and meticulous attention to surgical technique, excellent clinical and radiographic results can be achieved with a third-generation total knee arthroplasty system at intermediate followup.

LEVEL OF EVIDENCE

Therapeutic study, Level III-2 (retrospective cohort study).

Extensor mechanism failure associated with total knee arthroplasty: prevention and management

Extensor mechanism complications are the most commonly reported reasons for revision surgery after total knee arthroplasty and are a frequent source of postoperative morbidity. Patellofemoral instability is the most commonly reported extensor mechanism complication and has multiple etiologies, including prosthetic malalignment and soft-tissue imbabalce. Patellar fracture or rupture of either the quadriceps or patellar tendon can cause catastrophic disruption of the extensor mechanism. Although some stable fractures can be successfully managed nonsurgically, displaced fractures or tendon rupture often lead to poor results. Other complications include patellar clunk and soft-tissue adhesions, prosthetic wear or loosening, and osteonecrosis. Increased understanding of implant alignment, rotation, and soft-tissue balance, as well as improved design of the trochlear groove of femoral implants and patellar components, has resulted in a decline in extensor mechanism complications. Appropriate prosthetic selection and meticulous surgical technique remain the keys to avoiding unsatisfactory results and revision surgery.

Effect of femoral component design on unresurfaced patellas in knee arthroplasty

Three total knee designs were evaluated to test the hypothesis that femoral component design affects the clinical and mechanical functions of the unresurfaced patella after total knee arthroplasty. Patients with the Ortholoc II, Advantim, and Profix femoral components were followed up for as many as 14 years and revision rate, anterior knee pain, and generalized knee pain were compared. A laboratory protocol was devised to evaluate pressure in the patellofemoral joint of knees from cadavers with a pressure-sensitive transducer using the same three designs at various degrees of knee flexion. Thirty Ortholoc II knee components were followed up for 14 years. Nineteen patients (63%) had severe anterior knee pain and 15 patients (50%) had reoperation to resurface the patella within 2 years. Two hundred one patients (222 knees) with Advantim components were followed up for 10 years and 305 patients (330 knees) with Profix components were followed up for 5 years. No patients with these two knee designs had severe anterior knee pain or reoperation for patellar resurfacing. A significantly higher rate of mild anterior knee pain was seen in the patients with Advantim components than in the patients with Profix components. No apparent relationship was seen between the severity of patellar wear found at the time of surgery and the incidence of anterior knee pain. Patients with rheumatoid arthritis receiving either the Advantim or Profix knee component performed as well as patients with osteoarthritis when the patella was not resurfaced. Pressure was significantly higher in the patellofemoral joints of the laboratory knee specimens with Ortholoc II components than in the specimens with either the Advantim or Profix components. The specimens with Advantim components had significantly higher pressure than did the specimens with normal knees, and the specimens with Profix components differed little from those with normal knees.

Changes in patellar tracking after total knee arthroplasty: 10-year follow-up of Miller-Galante I knees

Changes in patellar tilt angle and patellar displacement were evaluated in 18 knees with the Miller-Galante I knee arthroplasty system (Zimmer, Warsaw, Ind). Mean follow-up was 10 years. Patellar tilt angle at final follow-up (5.7 degrees) was significantly larger than at 1 year postoperatively (2.8 degrees). Patellar displacement at final follow-up (5.1 mm) was significantly larger than at 1 year postoperatively (3.4 mm). Preoperatively, patellar tilt angle showed a statistically significant correlation with the change in tilting angle during follow-up. These results suggest patellar tracking can worsen during the long-term postoperative period.

Comparison of fixed-bearing and mobile-bearing total knee arthroplasties

The purpose of the current study was to directly compare the results of fixed-bearing and mobile-bearing total knee arthroplasties in the same patient who had bilateral simultaneous total knee replacements. A fixed-bearing total knee prosthesis (AMK) was implanted in one knee and a mobile-bearing total knee prosthesis (LCS) was implanted in the other knee in 116 patients. The average age of the patients was 65 years (range, 33-70 years). The average followup was 7.4 years (range, 6-8 years). Clinical and radiographic followup was done using Knee Society and Hospital for Special Surgery knee rating systems at 6 weeks, 3 months, 6 months, 1 year after surgery, and yearly thereafter. Total knee score, pain score, mean functional score, and range of motion were comparable in both groups. Two knee replacements (2%) in one patient with AMK prostheses were revised because of complete wear of tibial bearing polyethylene. One knee replacement (1%) in one patient with an LCS prosthesis was revised because of dislocation of the medial tibial bearing polyethylene and one knee replacement (1%) in one patient with an LCS prosthesis was revised because of complete wear of the medial tibial bearing polyethylene. No knee had aseptic loosening or osteolysis in either group. After a minimum followup of 6 years, the results of fixed- and mobile-bearing total knee prostheses in the current series are favorable. However, there is no evidence to prove the superiority of the mobile-bearing total knee design.

Long-term followup of cementless versus hybrid fixation for total knee arthroplasty

In a prospective trial, 99 patients (100 knees) with osteoarthritis were randomized to either cementless or hybrid fixation of cruciate-retaining Miller-Galante-I total knee arthroplasties between January 1987 and December 1988. Thirty-one patients died during the study period and two additional patients were lost to followup, leaving 67 total knee arthroplasties for analysis. Thirty-nine patients underwent revision surgery at an average of 6.9 years postoperatively. The main reason for revision surgery was failure of metal-backed patellas with 25 knees revised at an average of 7.4 years, and the second most common reason was tibial polyethylene failure. Survival curves showed 60% survival at 14 years for all knees, and 85% survival at 14 years when failures for metal-backed patellas and infection were excluded, with no significant difference between the two groups. Failure of metal-backed patellas was significantly higher in the cementless group. Tibial polyethylene failure occurred in five of the hybrid group and none of the cementless group, but this was not a significant difference. Surviving prostheses were assessed at an average of 12.8 years (range, 11.5-13.5 years). Average clinical scores were 94.8 points preoperatively, and 143 points at the latest followup, with significantly higher scores in the hybrid group. Differences in outcome between the two groups were not sufficiently significant to recommend one method of fixation over another. With elimination of poor design features related to the patellofemoral articulation and thin tibial polyethylene, cruciate-retaining total knee arthroplasties can yield good durable results, whether cementless or hybrid fixation is used.

Intermediate-term clinical and radiographic results of Synatomic and AGC knee prostheses

This study compared two total knee prostheses to determine whether the clinical and radiographic outcomes were different, focusing primarily on the patellofemoral articulation. The study group was comprised of 75 Synatomic (short-stemmed, anatomic VF type) and 79 AGC 2000 (universal, nonanatomic) prostheses. Patients underwent follow-up for an average of 63 and 50 months, respectively. At latest follow-up, the mean knee joint score was 84.4 in the Synatomic and 86.5 in the AGC group. Mean knee function scores were 63.5 and 63.4, respectively. No statistically significant difference was noted between the two prostheses.

Current concepts review: symmetry versus asymmetry in the design of total knee femoral components--an unresolved controversy

Despite the excellent success of earlier total knee replacement designs such as the Total Condylar Knee (Johnson & Johnson, Raynham, MA), which had a symmetrical femoral component, the majority of modern designs feature a more anatomic and asymmetric femoral prosthesis. A raised lateral phalange, an angled trochlear groove, or both are thought to improve patellar tracking. Laboratory studies, however, suggest that surgical technique may be the dominant factor in determining patellofemoral kinematics. Component design has not been proven to be significant. A prosthesis with asymmetric femoral components may cost more. The literature reviewed in this article finds no advantage to the use of asymmetric versus symmetrical femoral components in total knee replacement.

Clinical and radiologic survivorship of cementless tibial components fixed with finned polyethylene pegs

One hundred twenty patients (22 men, 98 women; 144 knees) with uncemented Freeman-Samuelson total knee arthroplasty were followed prospectively. Eighty-one patients had rheumatoid arthritis and 39 patients had osteoarthrosis. The mean follow-up period was 6.8 years. Three different types of tibial components were used: a high-density polyethylene component without stem, a metal-backed tibial component without stem, and a metal-backed tibial component with stem. Progressive varus tilting turned out to be an early sign of failure and occurred in 22% of the tibial components. Revision of the tibial component was done in 17 knees. Survival analysis with revision as endpoint revealed a survival rate of 79% at a follow-up period of 10 years. Cementless fixation of this design using macrointerlocking pegs and no other stabilization resulted in poor fixation and a high revision rate and cannot be recommended.