Bilateral Total Hip and Knee Arthroplasties: Average 10-Year Follow-Up.

BACKGROUND: The present study investigates the clinical and radiographic outcomes in patients with all 4 major lower extremity joints replaced. METHODS: A retrospective review of our institution's database identified 125 patients in whom both hips and both knees were replaced. The mean time between the first and last arthroplasty was 6.6 years. Preoperative diagnoses included osteoarthritis in 80% and rheumatoid arthritis in 20%. The average age at the time of the first arthroplasty was 63.7 years. The mean follow-up for all arthroplasties was 10.5 years (range 2-31 years). Patients were then matched according to age, gender, diagnosis, prosthesis, and follow-up, to patients with single or bilateral total hip or total knee arthroplasty. RESULTS: There were 11 aseptic hip revisions (4.4%) and 3 aseptic knee revisions (1.2%). At final follow-up, 86% of hips and 83% of knees were rated with no or mild pain, 68% of patients rated walking as unlimited, and 98% of patients were able to satisfactorily negotiate stairs. Aseptic survivorship for all joint arthroplasties was 93.8% at 15 years. No statistical differences were noted in pain, function, stair, and walking scores between the matched groups. CONCLUSION: This report demonstrated excellent clinical, functional, and radiographic outcomes in patients with all 4 major lower extremity joints replaced. Walking aids were needed in 15% of patients, however. At final follow-up, this selected group of patients appears to fare just as well as patients with single or bilateral hip or knee arthroplasty with respect to pain and function.

Ten-Year Outcome Comparison of the Anatomical Graduated Component and Vanguard Total Knee Arthroplasty Systems.

UNLABELLED: The development of a new total knee system as a successor prosthesis in total knee arthroplasty (TKA) requires clinical outcome improvement. 10,843 TKAs were performed of which 9169 utilized the Anatomical Graduated Component (AGC) and 1674 utilized the Vanguard prosthesis (both Biomet, Warsaw, IN). Survival rates at ten years postoperatively for the AGC and Vanguard were 98.7% and 98.4% (P=.4897) respectively. The top reasons for component failure were loosening (AGC: 0.29%, Vanguard: 0.30%), polyethylene wear, and instability (AGC: 0.13%, Vanguard: 0.12%). These results reveal similar outcomes in both designs, with relatively few revisions and high survival rates at ten years postoperatively. SUMMARY: This abstract offers data concerning the usefulness of the Vanguard Total Knee System as a successor to the Anatomical Graduated Component.

"Thicker" polyethylene bearings are associated with higher failure rates in primary total knee arthroplasty.

"Thin" modular polyethylene bearings have previously been associated with failure from wear. This study examined the influence of polyethylene thickness on survivorship in primary total knee arthroplasty (TKA). Do "thinner" or "thicker" bearings fail more? Six thousand seventy primary TKAs with a single implant design were reviewed. The failure rate in knees with bearings 14 mm or less was 0.7%, whereas the failure rate of knees with bearings 16 mm or greater was 2.3% (P < .0001; hazard ratio, 3.2). No knee was revised for polyethylene wear. Thicker bearings did not directly cause failure, but factors that lead to the insertion of a thicker bearing such as a deeper tibial resection and ligament imbalance may contribute to the observed increased failure. The significant influence of this often-unrecognized surgical variable has not been previously reported and must be carefully considered during TKA.

High preoperative range of motion is a significant risk factor for dislocation in primary total hip arthroplasty.

Dislocation after total hip arthroplasty (THA) is multifactorial and is dependent on surgical, implant, and patient factors. We hypothesized that high preoperative hip range of motion is an important variable contributing to instability after THA. We retrospectively reviewed 3379 THAs performed during a 21-year period. Average follow-up was 6.6 years. We examined the effect of surgical approach, femoral head size, and preoperative range of motion on dislocation rates. Patients with a posterior approach and 115 degrees or greater of combined preoperative flexion, adduction, and internal rotation dislocated at a significantly higher frequency than those with less than 115 degrees of combined motion (odds ratio, 1.9; P = .007). High preoperative motion in conjunction with a posterior approach and femoral head size less than 32 mm had the highest dislocation rate in our sample (5.9%). Preoperative range of motion is an important variable that should be taken into consideration during operative planning to help reduce the risk of dislocation.

Extended femoral osteotomy and proximally coated prosthesis for hip revision.

Extended trochanteric osteotomy facilitates femoral reconstruction in revision total hip arthroplasty. This study examined the outcome of extended trochanteric osteotomy combined with a proximally porous-coated calcar replacement prosthesis during revision total hip arthroplasty. Forty-five cases were reviewed with an osteotomy union rate of 98%. No femoral component was loose radiographically, and none were revised for loosening. These findings indicate excellent short-term clinical and radiographic results can be achieved with an extended trochanteric osteotomy and proximally porous-coated calcar replacement prosthesis.

Manipulation after total knee arthroplasty.

BACKGROUND: Following total knee arthroplasty, some patients who fail to achieve >90 degrees of flexion in the early perioperative period may be considered candidates for manipulation of the knee under anesthesia. The purpose of this study was to assess the outcomes of manipulation following total knee arthroplasty. METHODS: One hundred and thirteen knees in ninety patients underwent manipulation for postoperative flexion of < or =90 degrees at a mean of ten weeks after surgery. Flexion was measured with a goniometer prior to total knee arthroplasty, at the conclusion of the operative procedure, before manipulation, immediately after manipulation, at six months, and at one, three, and five years postoperatively. RESULTS: Eighty-one (90%) of the ninety patients achieved improvement of ultimate knee flexion following manipulation. The average flexion was 102 degrees prior to total knee arthroplasty, 111 degrees following skin closure, and 70 degrees before manipulation. The average improvement in flexion from the measurement made before manipulation to that recorded at the five-year follow-up was 35 degrees (p < 0.0001, paired t test). There was no significant difference in the mean improvement in flexion when patients who had manipulation within twelve weeks postoperatively were compared with those who had manipulation more than twelve weeks postoperatively. Patients who eventually underwent manipulation had significantly lower preoperative Knee Society pain scores (more pain) than those who had not had manipulation (p = 0.0027). CONCLUSIONS: Manipulation generally increases ultimate flexion following total knee arthroplasty. Patients with severe preoperative pain are more likely to require manipulation.

The effect of stuffing the patellofemoral compartment on the outcome of total knee arthroplasty.

BACKGROUND: The effect of so-called stuffing of the patellofemoral compartment at the time of total knee arthroplasty (that is, increasing the anterior patellar displacement, the anteroposterior femoral size, or the combined anteroposterior patellofemoral size) has not been well studied. The purpose of the present study was to evaluate the effect of stuffing the patellofemoral compartment on the outcome of primary total knee arthroplasty. METHODS: A retrospective review of 1100 primary total knee arthroplasties that had been performed in 1997 and 1998 was conducted. Eight hundred and thirty arthroplasties (75.5%) met the diagnostic and minimum two-year follow-up criteria for inclusion in this report. Radiographic measurements were made to determine preoperative and postoperative anterior patellar displacement, anteroposterior femoral size, combined anteroposterior patellofemoral size, anterior femoral offset, and posterior femoral offset. Regression analysis was performed to determine the effects of changes in these variables on the range of motion, the Knee Society Knee Score, the Knee Society Function Score, the Knee Society Pain Score, and the rate of lateral retinacular release. RESULTS: Preoperative to postoperative changes in anterior patellar displacement, anteroposterior femoral size, combined anteroposterior patellofemoral size, anterior femoral offset, and posterior femoral offset had no clinically meaningful effect on the range of motion of the knee or on any of the Knee Society scores. Increases in anterior patellar displacement were associated with a lower probability of the need for a lateral retinacular release. Increases in measured anteroposterior femoral size were associated with a higher probability of the need for lateral release. Even when combined, however, these relationships explained only 10.1% of the observed variance in the need for lateral retinacular release. Moreover, analyses indicated that patient gender, large as opposed to medium patellar size, and absolute femoral component size influenced the likelihood of lateral release more than did anterior patellar displacement and measured anteroposterior femoral size. CONCLUSIONS: Our findings do not support the widely held belief that stuffing of the patellofemoral joint results in adverse outcomes after total knee arthroplasty. Furthermore, the need for lateral release appears to be multifactorial and likely involves a more complex set of factors. Thus, without evidence of other identifiable causes of failure, we do not recommend revision for the treatment of pain of an overstuffed knee joint.

Total knee arthroplasty effectiveness in patients 55 years old and younger: osteoarthritis vs. rheumatoid arthritis.

In the past, total knee arthroplasty, although very successful, was only indicated for an elderly population. Recently though, several papers have been published confirming that total knee arthroplasty is effective in younger patients. This paper supports the results of those papers. In our study, 207 total knee arthroplasties were performed on patients 55 years old and younger using a posterior cruciate-retaining prosthesis. There was an overall survival rate of 97.6% with an average follow-up of 9.1 years. There were some minor variations in the outcome of the operation based on diagnosis (osteoarthritis vs. rheumatoid arthritis). The success also continued over time with an estimated survival rate of 94.8% at 12 years. Total knee arthroplasty is an effective operation in patients younger then 55 years old.

ACL Damage and Deficiency is Associated with More Severe Preoperative Deformity, Lower Range of Motion at the Time of TKA.

BACKGROUND: ACL status varies in the arthritic knee during TKA. QUESTIONS/PURPOSES: The purpose of this study was to examine clinical features and intraoperative findings associated with stages of ACL degeneration. METHODS: Coronal deformity, ROM, intra-articular degenerative patterns, and ligament releases were assessed for 1656 knees during TKA. Common patterns of deformity and severity of degenerative change were assessed as a function of the severity of ACL deficiency. RESULTS: Of the 1656 knees assessed, 27% had a normal ACL, 55% exhibited damage, and 18% exhibited complete absence of the ACL. Increased coronal deformity and lower preoperative ROM was associated with ACL deficiency. Increased chondral and meniscal damage and more extensive osteophyte formation were also found. More extensive ligament releases were required in ACL-deficient knees. CONCLUSIONS: The status of the ACL is predictive of the need for increased surgical deformity correction. A better understanding of ACL status is an important consideration during in choosing TKA as opposed to unicompartmental arthroplasty. The status of the ACL should be considered in planning for implant choice in TKA.

Midterm Results of the Vanguard SSK Revision Total Knee Arthroplasty System.

Revision total knee arthroplasty (TKA) is becoming increasingly common as the population ages and the number of existing primary TKAs continues to increase. Revision TKA systems use a greater range of component modularity than primary TKA systems, including stems, augments, and varying levels of constraint. The purpose of this study was to retrospectively review the authors' institution's use of one specific revision knee implant system and its midterm results. The Vanguard SSK Revision Knee System (Biomet, Warsaw, Indiana) was implanted 297 times in 272 patients between 2005 and 2013. Average patient age was 67.2 years, average body mass index was 33 kg/m(2), and average follow-up was 4.8 years. The most common diagnoses leading to use of this system were failed previous TKA (45.5%) and periprosthetic infection (23.2%). The SSK system was used in 78 (26.3%) complex primary TKAs at the discretion of the operating surgeon. There were 22 failures: 12 septic and 10 aseptic. Of the 12 infections, 6 occurred after 2-staged treatment of periprosthetic joint infection, with all 6 of these reinfections having a different causative organism. Aseptic failures included aseptic loosening (n=3), periprosthetic fracture (n=2), patellar maltracking (n=2), instability (n=1), arthrofibrosis (n=1), and extensor mechanism disruption (n=1). Aseptic implant survivorship was 97.2%, 95.6%, 93.1%, and 93.1% at 1, 3, 5, and 7 years postoperatively, respectively. The Vanguard SSK demonstrates excellent performance at medium-range follow-up with respect to complications, clinical scores, and prosthesis survivorship. [Orthopedics.2016; 39(5):e833-e837.].

The effect of femoral notching during total knee arthroplasty on the prevalence of postoperative femoral fractures and on clinical outcome.

BACKGROUND: The treatment of a supracondylar femoral fracture following total knee arthroplasty is complicated by the presence of the prosthetic components. Anterior femoral notching during arthroplasty has been implicated as a contributing risk factor for femoral fracture. We retrospectively reviewed the effect of anterior femoral notching on the subsequent occurrence of a periprosthetic supracondylar fracture of the distal aspect of the femur and the outcomes of primary total knee arthroplasty in such patients. METHODS: The prevalence and depth of femoral notching were determined on a review of the lateral radiographs by observers blinded to the clinical results of 1089 consecutive total knee replacements performed in 1997 and 1998. Linear and logistic regression modeling was used to analyze the relationship between femoral notching and the prevalence of supracondylar femoral fracture, postoperative range of motion, the Knee Society score, and the Knee Society functional and pain scores. RESULTS: Femoral notching was performed in 325 (29.8%) of the 1089 knees in our series. During an average follow-up period of 5.1 years, only two supracondylar femoral fractures occurred, both in femora treated without notching. Femoral notching was not associated with an increased rate of fracture (p = 1.000) or with significant differences in the measures of outcome (range of motion [p = 0.117], knee score [p = 0.967], functional score [p = 0.861], need for a lateral release [p = 0.234], or postoperative pain [p = 0.948]). CONCLUSIONS: This study demonstrated no difference in knees managed with or without notching of the anterior distal aspect of the femur with respect to the occurrence of a supracondylar fracture, range of motion, Knee Society score, Knee Society function, or pain.

The AGC all-polyethylene tibial component: a ten-year clinical evaluation.

BACKGROUND: While high success rates have been achieved in association with other all-polyethylene tibial components, an alarming number of failures have occurred at our institution in association with the use of an all-polyethylene version of the AGC tibial component. The purpose of the present study was to describe the survival of the AGC all-polyethylene tibial component. METHODS: Five hundred and thirty-six AGC all-polyethylene tibial components were implanted in 405 patients and were followed over a ten-year period. The average age of the patients at the time of surgery was 70.3 years, the average weight was 78 kg, and the most common diagnosis was osteoarthritis (prevalence, 92.9%). A clinical and radiographic analysis was performed, Knee Society knee and function scores were determined, and Kaplan-Meier survivorship analysis was conducted. Failure was defined as aseptic loosening as evidenced by progressive radiolucent lines and/or revision due to aseptic loosening or collapse. RESULTS: A high rate of failure was noted in the early postoperative period, with a survival rate of 90.04% (95% confidence interval, 87.35% to 92.72%) after three years. At ten years, the survival rate was 68.11% (95% confidence interval, 57.57% to 78.65%). Fifty-eight (73.4%) of seventy-nine failures occurred in association with loosening or collapse of the bone beneath the medial tibial plateau. CONCLUSION: While some all-polyethylene tibial designs have been successful, the low success rate among knees treated with the AGC all-polyethylene tibial component suggests that the results associated with all-polyethylene tibial components are design-sensitive. LEVEL OF EVIDENCE: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Minimum ten-year follow-up of a straight-stemmed, plasma-sprayed, titanium-alloy, uncemented femoral component in primary total hip arthroplasty.

BACKGROUND: The long-term results of total hip arthroplasty without cement have been reported only rarely. The purpose of the present study was to evaluate the minimum ten-year results of primary total hip arthroplasty performed with use of a proximally porous-coated, plasma-sprayed, straight-stemmed, titanium-alloy femoral component. METHODS: The clinical and radiographic results of a consecutive series of 105 total hip replacements in ninety-five patients were reviewed ten to twelve years postoperatively. The diagnosis was osteoarthritis for seventy-seven hips (73%). The clinical result was evaluated on the basis of the Harris hip score, complications, and thigh pain. A detailed radiographic analysis was performed at each follow-up visit. Kaplan-Meier analysis was performed to evaluate the survival of the femoral component. RESULTS: The average Harris hip score improved from 46 points preoperatively to 92 points postoperatively. The average pain score at the time of the most recent follow-up was 42 points, with eighty-three hips (79%) rated as pain-free. Thigh pain was identified in only two patients. All radiolucent lines were seen around the tip of the stem. All hips had some degree of femoral remodeling consistent with osseous ingrowth. No femoral component was revised, and no femoral component had evidence of loosening. Eight acetabular components were revised because of loosening and wear, and one was revised because of recurrent dislocation. One focal femoral osteolytic lesion was seen. CONCLUSIONS: This femoral component afforded durable fixation at ten to twelve years after primary total hip arthroplasty. LEVEL OF EVIDENCE: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

The Surgeon's Role in Relative Success of PCL-Retaining and PCL-Substituting Total Knee Arthroplasty.

BACKGROUND: The orthopedic literature has not shown a universal and replicated difference, outside of flexion, in clinical results between posterior cruciate ligament retention and posterior cruciate ligament substitution in total knee arthroplasty. QUESTIONS/PURPOSES: This study was performed to compare the restoration of flexion and knee function in a large series of cruciate-retaining and cruciate-substituting total knee arthroplasties (TKRs). In addition, we aimed to study how other variables, such as those unique to each surgeon, may have affected the results. PATIENTS AND METHODS: The current study evaluated 8,607 total knee arthroplasties in 5,594 patients performed by six surgeons, each using one of four prosthesis designs (two posterior cruciate ligament retaining, two posterior cruciate ligament substituting). Knees were compared at the level of cruciate-retaining and cruciate-substituting knees, at the level of the four prostheses, and at the level of surgeon-implant combinations. Least squared means scores were obtained through multiple linear regression, analysis of variance, and the maximum likelihood method. RESULTS: At the level of posterior cruciate ligament treatment, posterior cruciate ligament substitution as a whole showed 3.2° greater flexion than posterior cruciate ligament retention. At the prosthesis level, cruciate-substituting models provided greater flexion and cruciate-retaining models provided higher function scores. In the surgeon-implant combinations, surgeons provided mixed results that often did not reflect findings from other levels; one surgeon's use of a posterior cruciate ligament retaining prosthesis achieved 14.7° greater flexion than the surgeon's use of a corresponding posterior cruciate ligament substituting design. CONCLUSIONS: Posterior cruciate ligament treatment is confounded by other variables, including the operating surgeon. The arthroplasty surgeon should choose a prosthesis based, not only on outside results, but also on personal experience and comfort.

Clinical results of isolated tibial component revisions with femoral component retention.

The purpose of this study is to report the outcome for a consecutive series of isolated nonmodular tibial component revisions. A consecutive series of 6548 total knee arthroplasties (6024 metal backed; 524 all-polyethylene) were performed with nonmodular tibial components of which 54 knees (0.82%) (22 metal backed; 32 all-polyethylene) underwent isolated tibial component revision with femoral component retention. Clinical outcome and component survivorship were examined. Pain scores improved from 19 to 42 points and Knee Society score improved from 62 to 87 points after revision. At a mean of 6.6-year follow-up, the survivorship of the revised tibial components and retained femoral components, with aseptic loosening as the end point, was 100%.

Hybrid total knee arthroplasty: 13-year survivorship of AGC total knee systems with average 7 years followup.

A retrospective study of 201 anatomic graduated component total knee arthroplasties implanted with hybrid fixation at the authors' center was performed in response to conflicting data in the literature concerning the benefits of a hybrid method. Selection for hybrid fixation was nonrandomized and based on femoral component fit. Survivorship analysis was performed, and rates of radiolucent lines surrounding the femoral component and occurrence of osteolysis were noted. At 7 and 13 years, survivorship with tibial or femoral revision as the end point was 0.9926 and 0.9732, respectively. Radiolucencies were found adjacent to 15 femoral components at final followup (seven in Zone 1, three in Zone 2, five in Zone 3, one in Zone 4, two in Zone 5, zero in Zone 6). Osteolysis was observed in one knee after secondary evaluation. Hybrid fixation in a selected patient population can result in excellent results in middle to long-term followup.

Early failure of unicompartmental knee arthroplasty leading to revision.

The most common previously reported modes of failure of unicompartmental knee arthroplasty (UKA) in the first and second decades are polyethylene wear, progression of arthritis, and component loosening. The purpose of this study is to describe an early mechanism of failure of the medial UKA. Thirty-two consecutive revisions from UKA to total knee arthroplasty were retrospectively reviewed. The predominant mode of failure observed in 15 (47%) of 32 knees was medial tibial collapse. Of these, 87% were an all-polyethylene design, and 7 of 15 failed in less than 16 months and required more complex reconstruction with stems, augments, and screws and cement. Increased tibial slope was associated with posterior tibial collapse. In our series, knees that failed by medial tibial collapse had more significant bone defects and required more complex reconstructions than is currently reported in the literature.

Polyethylene sterilization and production affects wear in total hip arthroplasties.

Production and package sterilization techniques for the polyethylene used in acetabular components for total hip arthroplasties are known to affect wear. We considered three combinations of techniques: sterilization by radiation in inert gas with isostatically molded polyethylene, in inert gas and ram-extruded polyethylene, and in air with extruded polyethylene. The intent of this study was to confirm that molded polyethylene and polyethylene radiated in inert environments reduce wear rates in vivo, to determine the combination of methods with the least wear, and to determine how much variance in wear is attributable to these methods. We reviewed 150 consecutive total hip arthroplasties done in 133 patients using 28-mm cobalt-chrome femoral heads and polyethylene-lined, titanium, ring-locked acetabular components. The least wear occurred in gamma inert-molded polyethylene components. The mean volumetric wear rates were 52.12 mm3/year for gamma inert-molded, 62.32 mm3/year for gamma inert-extruded, and 66.09 mm3/year for gamma air-extruded polyethylene components. Relative risk assessment found gamma air-extruded and gamma inert-extruded polyethylene components to wear 16% and 11% more than gamma inert-molded polyethylene components, respectively. Gender, body mass index, and age accounted for the greatest amount of the explained variance in volumetric wear (57.5%, 21.6%, and 14.4, respectively), followed by angle of wear (3.4%), and sterilization and production technique (3.2%).

A clinical comparison of patellar tracking using the transepicondylar axis and the posterior condylar axis.

Two different methods for femoral component rotation in total knee arthroplasty (TKA) were compared with regard to the need for lateral retinacular release and 3-year follow-up knee society scores of both patellofemoral function and 3-year radiographs of the patella. The posterior condylar axis was used in 1322 consecutive primary TKAs, and the transepicondylar axis (TEA) was used in 1059 consecutive primary TKA. A significant decrease in lateral retinacular release was observed from 56.9% (752 knees) using the posterior condylar axis down to 12.3% (130 knees) using the TEA. No significant differences in knee society scores were observed between the 2 groups with regard to stair climbing, pain, patella radiographs, or range of motion. Routine use of the TEA is recommended for determining femoral component rotation in TKA.