Total condylar knee replacement: a 20-year followup study.

Between 1976 and 1979, 220 total knee replacements were done on 164 patients using the Total Condylar Knee replacement. The diagnosis was rheumatoid arthritis in 111 knees and osteoarthritis in 109 knees. Patients with 157 knees are known to have died as of December 1998, leaving 63 knees in patients who are still alive. Twelve patients with 18 knees were lost to followup. The average 20-year followup data (range, 18-22 years) are presented for 45 knees in 30 patients using Knee Society evaluations. The average Knee Society clinical score for the surviving patients was 88 points, and the average functional score was 58 points. The radiographic followup averaged 19 years. The average overall alignment was 3 degrees valgus. Femoral lucencies were present in 17 of 40 adequate lateral views, most commonly about the anterior and posterior surfaces. Two femoral components were loose. Twenty-two tibial components had radiolucencies; four radiolucencies were circumferential. The remaining 41 knees retained a well-fixed cemented central peg despite proximal interface lucencies. From the group of 220 knees, 14 revisions have been done at an average of 11.4 years postoperative. Two knee replacements were revised for isolated tibial loosening, whereas one knee replacement had isolated femoral loosening. Three knee replacements were revised for loosening of both components, and one was revised for isolated patellar loosening. Four patients had sepsis develop; three of these four patients were treated with two-stage revision, and one underwent fusion. Three patients were treated for supracondylar fractures. The Total Condylar Knee replacement maintains excellent durability at 20-years followup.     

An algorithm for the posterior cruciate ligament in total knee arthroplasty.

The fate of the posterior cruciate ligament in primary total knee arthroplasty is controversial. An algorithmic approach is presented that is based on pathologic criteria for evaluating and treating patients with primary total knee arthroplasty that will aid in the posterior cruciate ligament decision-making process, producing more predictable procedures and outcomes. A consecutive series of the first 120 patients (171 knees) who had primary posterior cruciate-retaining arthroplasty and the first 120 patients (180 knees) who had primary posterior-stabilized arthroplasty with a minimum 5-year followup in which the Maxim Complete Total Knee System and the algorithmic approach were used were compared. No statistically significant differences in outcome between the groups were observed. Among the patients who had posterior cruciate-retaining arthroplasty, no revisions attributable to aseptic loosening have been reported at an average followup of 6.39 years. The average followup Knee Society total score was 162.16 points, with 91 (54.8%) knees having excellent outcome ratings. No revisions attributable to aseptic loosening have been reported among the patients who had posterior-stabilized arthroplasty at an average followup of 5.98 years. The average followup Knee Society total score was 158.05 points, with excellent outcome ratings reported in 96 (54.9%) knees. The use of a standardized algorithm has streamlined the treatment of patients having primary total knee arthroplasty, consistently providing excellent clinical results when either retaining or sacrificing the posterior cruciate ligament.     

Total knee arthroplasty after high tibial osteotomy

Between 1980 and 1995, 95 consecutive total knee replacements were performed at an average of 10 years 4 months after high tibial osteotomy. The average age of the 82 patients was 66 years, with a preoperative diagnosis of osteoarthritis in 94 knees. One patient died 6 months after surgery. The followup of the remaining 81 patients (94 knees) averaged 8.6 years (range, 2-17 years). Knee Society knee score at final followup improved to an average of 87.6 points from a preoperative average of 38.1 points. No pain was present in 86.2% of knees, and 12.8% of knees had only mild or occasional pain. Tibial radiolucencies were identified in 12 (12.8%) knees at final followup, and in only four knees were radiolucent lines found about the lateral zones. Only one tibial component required revision 3 years after surgery. Although no preoperative factor was identified that predisposed to an inferior knee score, function score, or pain score, the severity of the preoperative flexion contracture and the number of previous surgeries did relate to diminished postoperative motion. However, an increased number of patellar radiolucencies were seen in the knees in which the lateral joint line was raised (referenced from the fibular head) a greater degree. The clinical results of total knee replacement after high tibial osteotomy appeared similar to those of primary total knee replacement. The previous high tibial osteotomy had no adverse effect on the eventual results of a cemented posterior cruciate retaining total knee replacement.     

Rotating hinge total knee arthroplasty in severly affected knees

A consecutive series of 24 knees in 21 patients who received a Finn rotating hinge for primary (nine knees) or revision (15 knees) total knee arthroplasty between August 1993 and January 1997 was reviewed. The average followup was 33 months (range, 21-62 months) for all patients in the study. Seventeen patients (20 knees) were followed up for more than 2 years. Twenty-four knees (21 patients) were categorized according to Knee Society scoring criteria: 37.5% (nine knees) were Category A, 25% (six knees) were Category B, and 37.5% (nine knees) were Category C. Using the Knee Society knee and function scores, clinical and radiographic results were assessed and outcome analysis was determined. The average Knee Society knee score improved from 44 points (range, 5-64 points) before surgery to 83 points (range, 45-95 points) after surgery; the average functional score according to the Knee Society system improved from 10 points (range, 0-35 points) before surgery to 45 points (range, 0-100 points) after surgery. Pain and function markedly improved after surgery. For treatment of the most severely affected knees with compromised bone and ligamentous instability, the Finn total knee replacement appears to be an acceptable option. As a rotating hinge design, the prosthesis at early followup provides excellent pain relief, restoration of walking capacity, and stabilization, without evidence of early mechanical failure.     

Primary constrained condylar knee arthroplasty for the arthritic valgus knee

The purpose of the current study was to review results of primary constrained condylar knee arthroplasty in elderly patients with genu valgum deformity. The hypotheses were: (1) constraint has no adverse effects in elderly patients; (2) treating deformity with a constrained condylar knee prosthesis in lieu of lateral ligament release avoids morbidity, particularly peroneal nerve palsy and flexion instability; and (3) press-fit noncemented stem extensions enhance fixation of the cemented core components and are not prone to loosening. Between 1988 and 1993, 44 consecutive primary Constrained Condylar Knee prostheses were implanted in 37 patients (average age, 72.7 years) with an average valgus angle of 17.6 degrees. Indications for the Constrained Condylar Knee implant were: elderly patients with genu valgum deformity and medial collateral ligament incompetence. Outcome was assessed prospectively using the Hospital for Special Surgery and Knee Society scoring systems; followup was by independent observer. Clinical and radiographic followup (average, 7.8 years) was available for 28 knees (26 patients). The Hospital for Special Surgery score improved from 52.2 to 89.6 points. The average Knee Society score and functional scores improved from 27.4 and 32.4 points to 95.2 and 67.2 points, respectively. At followup, the average alignment based on anteroposterior radiographs obtained with the patient weightbearing was 5.3 degrees. No radiographic loosening, prosthetic failures, peroneal nerve palsies, or flexion instability occurred. No failures occurred in the 11 patients (16 knees) who died before the latest followup. To the authors' knowledge, this is the largest reported series with the longest reported followup of patients with primary Constrained Condylar Knee prostheses. The use of the Constrained Condylar Knee prosthesis for elderly patients with low physical demands with genu valgum resulted in significant pain relief and improved function.     

Revision total knee arthroplasty with the Total Condylar III system: A comparative analysis of 71 consecutive cases of osteoarthritis or inflammatory arthritis

Background?As revision total knee arthroplasty surgery is becoming more common, it is necessary to evaluate how individual revision prosthesis systems perform in degenerative and inflammatory arthritides. In this study, results of the use of the Total Condylar III (TC III) system in osteoarthritis (55 knees) were compared to results of its use in inflammatory arthritis (16).

Methods?Patients were followed radiographically for 5.9 (3.0–10.2) years and clinically for 3.0 (0.2–6.8) years, using re-revision as the endpoint.

Results?At 1 year after revision and at final follow-up, the total Knee Society knee score, function score and range of motion had improved (p?<?0.001) with no differences between osteoarthritis and inflammatory arthritis. No knee had definite component loosening, although 23 knees had asymptomatic radiolucent lines. Complications comprised 4 infections, 1 patellar pain syndrome and 1 rupture of the patellar tendon. Using any re-revi-sion of the prosthesis as the endpoint, 5-year survival was 95% and 8-year survival was 94%.

Interpretation?Concentration of demanding revision knee arthroplasties to a few hands led to good or excellent knee joint knee score results in four-fifths of the patients, and showed good outcome with the TCIII system. In spite of ligamentous laxity, propensity to develop infections, bone destruction and poor general health, patients with inflammatory arthritis had results similar to those with osteoarthritis.     

Revision total knee arthroplasty with the total condylar III system: a comparative analysis of 71 consecutive cases of osteoarthritis or inflammatory arthritis

BACKGROUND: As revision total knee arthroplasty surgery is becoming more common, it is necessary to evaluate how individual revision prosthesis systems perform in degenerative and inflammatory arthritides. In this study, results of the use of the Total Condylar III (TC III) system in osteoarthritis (55 knees) were compared to results of its use in inflammatory arthritis (16). METHODS: Patients were followed radiographically for 5.9 (3.0-10.2) years and clinically for 3.0 (0.2-6.8) years, using re-revision as the endpoint. RESULTS: At 1 year after revision and at final follow-up, the total Knee Society knee score, function score and range of motion had improved (p < 0.001) with no differences between osteoarthritis and inflammatory arthritis. No knee had definite component loosening, although 23 knees had asymptomatic radiolucent lines. Complications comprised 4 infections, 1 patellar pain syndrome and 1 rupture of the patellar tendon. Using any re-revision of the prosthesis as the endpoint, 5-year survival was 95% and 8-year survival was 94%. INTERPRETATION: Concentration of demanding revision knee arthroplasties to a few hands led to good or excellent knee joint knee score results in four-fifths of the patients, and showed good outcome with the TCIII system. In spite of ligamentous laxity, propensity to develop infections, bone destruction and poor general health, patients with inflammatory arthritis had results similar to those with osteoarthritis.     

Knee stability in posterior cruciate ligament retaining total knee arthroplasty

Anteroposterior knee laxity was evaluated in 14 patients (19 knees) who had posterior cruciate ligament retaining total knee arthroplasty using the Miller Galante I prosthesis. The followup ranged from 87 to 118 months (average, 105.9 months), and the measurements were done using the KT-2000 arthrometer. The mean anteroposterior displacement with the knees with Miller Galante I prostheses was 10.1 mm at 30 degrees flexion and 8.1 mm at 75 degrees flexion. In the 15 knees with Miller Galante I prostheses with flexion greater than 90 degrees, seven had less stability at 75 degrees than at 30 degrees flexion. These knees were considered to have a nonfunctional posterior cruciate ligament, and they had a worse Knee Society score (81.1) than did the other eight knees with Miller Galante I prostheses (89.9). There were four knees in which the flexion was less than 90 degrees. In this study, approximately half of the knees with posterior cruciate ligament retaining total knee arthroplasty did not have good anteroposterior stability in flexion an average of 9 years after surgery.     

结构性植骨修复膝关节翻修术中严重骨缺损的临床效果及相关分析

目的探讨同种异体结构性植骨在膝关节翻修术中大块骨缺损中应用的临床效果和意义。方法1994～2001年芬兰坦佩雷大学医院应用单一翻修假体及同种异体骨结构性植骨治疗膝关节置换术大块骨缺损患者10例（膝）,男1例,女9例,平均年龄70岁（61—77岁）,平均随访5年（1～8年）,所有手术均由两名高年资专科医师执行,采取KSS评分评估术前术后膝关节功能。结果最后随访时,患者膝关节KSS评分由术前的平均39分（4～51分）提高至81分（28—102分;P〈0．05）;疼痛评分由术前的18分（0—30分）提高至42分（10—50分;P〈0．05）。2例出现假体周围透亮线（〈1mm）,但没有任何松动症状;所有结构性植骨均获得满意的愈合,最后随访时没有出现吸收征象,1例患者术后出现膝前疼痛,经髌骨表面置换后症状消失。结论同种异体骨结构性植骨应用在膝关节翻修术中大块骨缺损中可取得满意的临床效果,重建下肢力线、第三代骨水泥技术的应用及有由专科医师实施手术是获得良好临床效果的保证。     

Ten- to 12-year followup of the Insall-Burstein I total knee prosthesis

The Insall-Burstein Posterior Stabilized knee prosthesis (Insall-Burstein I), developed at The Hospital for Special Surgery in 1978, has a metal-backed nonmodular tibial component. The polyethylene articular surface was directly molded. The purpose of the current study was to evaluate long-term wear with this design. The first 100 total knee arthroplasties (86 patients) performed by the senior author were followed prospectively. The average age of the patients at the time of surgery was 69.7 years (range, 45-89 years). The primary diagnoses were osteoarthritis in 77 knees (66 patients), inflammatory arthritis in 17 knees (14 patients), and posttraumatic arthritis in the remaining six knees (six patients). Thirty-eight knees (35 patients) had varus angulation, 14 knees (13 patients) had valgus angulation, and 48 knees (40 patients) had a 0 degrees to 10 degrees tibiofemoral angle preoperatively. All patients were evaluated at 10 to 12 years followup. Knee Society scores and radiographs were obtained. Thirty-six knees were in 30 patients who had died and two knees were in two patients who were infirm. Telephone evaluation only was available for eight knees (seven patients), leaving 54 knees (47 patients) for direct clinical and radiographic evaluation. No patients were lost to followup. The average Knee Society clinical score at latest followup was 91.6 points. The average function score was 69 points. One knee arthroplasty failed because of tibial loosening, one failed because of patella wear and fracture, two failed because of sepsis, and two failed because of nonspecific pain. There were seven patella fractures (7%) in the 100 knees. One of the fractures resulted in a total knee revision (noted above), two resulted in patellar component revision, and another resulted in patellar component removal. The remaining three patella fractures were discovered incidentally and were asymptomatic. There were no patellar dislocations. At long-term radiographic analysis, valgus alignment averaged 6 degrees (range, 0 degrees-11 degrees). Polyethylene wear averaged 0.40 mm. There was no catastrophic wear of tibial polyethylene. Thirty-two knees in 32 patients (65%) had radiolucencies in at least one zone; no lucency filled a zone, and none was wider than 2 mm. The absence of clinically significant tibial polyethylene wear at long-term followup is of particular interest. The performance of the molded, nonmodular polyethylene articulation is encouraging and needs to be analyzed critically against the more widely used machined, modular components used today.     

The kinematic rotating hinge prosthesis for complex knee arthroplasty.

Fifty-eight patients (69 knees) treated with the Kinematic Rotating Hinged knee prosthesis for complex primary and salvage revision total knee arthroplasty were followed up for an average of 75.2 months (range, 24-199 months). The indications for use of the Kinematic Rotating Hinged knee prosthesis included severe bone loss combined with ligamentous instability (30 knees), nonunion of a periprosthetic fracture (10 knees), an acute periprosthetic fracture (nine knees), severe collateral ligamentous instability (five knees), reimplantation for infection (six knees), nonunion of a supracondylar femoral fracture (four knees), congenital dislocation of the knee (three knees), and treatment of a severely comminuted distal femur (two knees). At the time of surgery, the average patient age was 72 years (range, 46-92 years). Preoperatively, knee extension averaged 4.94 degrees (range, 0 degrees-40 degrees) and flexion averaged 81 degrees (range, 15 degrees-125 degrees). At final followup, knee extension averaged 1.25 degrees (range, -5 degrees-25 degrees) and flexion averaged 94.2 degrees (range, 5 degrees-125 degrees). The preoperative Knee Society Knee score averaged 40.3 points (range, 2-93 points) and improved to 77 points (range, 33-99 points) at final followup. Complications were numerous: 23 (32%) patients experienced at least one complication and 12 (17%) patients had two or more complications. Deep periprosthetic infection was the most common complication (14.5%), followed by patellar complications (13%), and prosthetic component breakage (10%). During the period of this study, there were 15,798 primary and 2673 revision total knee arthroplasties done at the authors' institution. The patients receiving a Kinematic Rotating Hinged knee prosthesis represent a highly complex and small subset (0.37%) of the overall population having knee arthroplasty. Although the use of the Kinematic Rotating Hinged knee prosthesis for these limited indications has been useful for the authors, the incidence of complications and the poor outcome of these complications is disconcerting. Hinged total knee arthroplasty should be reserved for the final salvage option of the treatment options available when doing complex primary and salvage revision knee arthroplasties.     

Total knee arthroplasty with retention of both cruciate ligaments. A nine to eleven-year follow-up study.

BACKGROUND: Although many early designs of total knee arthroplasty allowed the retention of both cruciate ligaments, in most current designs of knee replacement systems, either both cruciate ligaments are removed or the posterior cruciate ligament alone is retained. This report is a review of a series of total knee arthroplasties in which both cruciate ligaments were retained. METHODS: The results of 163 total knee arthroplasties (130 patients) in which both cruciate ligaments were retained were assessed prospectively. One hundred and seven knees (eighty-nine patients) were followed for an average of ten years. There were thirty-four men and ninety-six women, and the average age at the time of the index arthroplasty was sixty-seven years (range, forty-two to eighty-four years). The diagnosis was osteoarthritis in 122 (75 percent) of the knees and rheumatoid arthritis in forty-one (25 percent). Twenty-six knees had a valgus deformity, 109 had a varus deformity, and twenty-eight had a normal alignment of 5 to 10 degrees of valgus. The anterior cruciate ligament was relatively normal in ninety-six knees and was partly degenerated in sixty-seven knees. With use of the rating system of the Knee Society, all 163 knees were prospectively evaluated at yearly intervals; fifty-six of these knees (in forty-one patients) were followed in this manner until the patient died or was lost to follow-up. RESULTS: One hundred and four (97 percent) of the 107 knees available for study at an average of ten years had an excellent or good result. At the time of the latest follow-up, pain was adequately relieved in ninety-seven knees (91 percent) and the average range of flexion was 107+/-12.6 degrees (range, 65 to 135 degrees). Ninety-five knees (89 percent) had normal anteroposterior stability (less than five millimeters of movement in this plane), and twelve knees (11 percent) had five to ten millimeters of movement as demonstrated by the drawer sign. Ninety-six knees (90 percent) had normal mediolateral stability, and eleven (10 percent) had 5 to 10 degrees of laxity. Ninety-four knees (88 percent) had valgus alignment of 5 to 10 degrees. The average knee score was 91+/-8.4 points (range, 54 to 100 points), and the average functional score was 82+/-21 (range, 10 to 100 points). The survival rate at ten years, with revision as the end point, was 95+/-2.0 percent. Seven (4 percent) of the 163 knees in this series were revised. There were no revisions for patellar problems or aseptic loosening of the tibial component. CONCLUSIONS: The good anteroposterior stability in this series after an average follow-up period of ten years indicates that both the anterior and the posterior cruciate ligaments, even when partly degenerated, remain functional when they are preserved in a total knee arthroplasty.     

Synovitis and artificial ligaments.

Sixty anterior cruciate Dacron prosthetic ligaments were placed arthroscopically in 57 patients from 1983 to 1985. Fifty-five of the 57 patients were followed for an average of 4.4 years. The complication rate at 13 months was 29%; at 4.4 years, 43%. There were 34 reoperations. In 16 knees (28%) the prosthesis had to be removed due to abrasion and arthritis with rupture of the prosthesis. Thirteen knees had chronic synovitis and one knee had bacterial infection, all of which were managed with arthroscopic debridement. Four knees required removal of the extraarticular staple. Clinical testing in 42 knees with the Dacron prosthesis still in place showed the Lysholm score improved from a preoperative score of 43 points to a score of 82 points after 5 years. Of the knees, 58% had a pivot shift of 2(+)-3+: a trace pivot shift in 30%; a negative pivot shift in only 12%. The KT-1000 arthrometer verified those pivot shifts. The results of this study are discouraging. The procedure was complicated by a high reoperation rate, usually secondary to arthritis. The impression was that although stability of the knee was improved by use of an artificial anterior cruciate ligament, the end result of the therapeutic procedure was the development of an iatrogenic model of degenerative arthritis in the human knee.     

Clinical and radiographic results of the total condylar III and constrained condylar total knee arthroplasty

The Total Condylar III (Johnson and Johnson, Braintree, MA) and Constrained Condylar (Zimmer, Warsaw, IN) knee prostheses are nonlinked, semi-constrained prosthetic alternatives to rigid or rotating hinge prostheses for use in complex knee reconstructions. Forty-six Total Condylar III or Constrained Condylar prostheses were implanted with cement in 36 patients and followed for a mean of 5 years (range, 2–9 years). There were 25 primary total knee arthroplasties and 21 revision total knee arthroplasties. The knees were evaluated using The Hospital for Special Surgery 100-point knee rating system. Overall, 40 knees (87%) had a good or excellent clinical result, 2 knees (4%) had a fair result, and 4 knees (9%) had a poor result. There was one revision for loosening of a cemented, nonmodular Constrained Condylar prosthesis, and one knee had a debridement for a late, metastatic infection, but the components were retained. There were no mechanical failures in those knees that were primary arthroplasties, but two mechanical failures occurred in those knees that were revision arthroplasties. Radiographic review showed one asymptomatic loosening of a Constrained Condylar tibial component with an uncemented press-fit stem, and only 8 knees had scattered nonprogressive tibial bone—cement radiolucent lines. The Total Condylar III and Constrained Condylar semiconstrained prostheses are successful when used in complex knee reconstructions.     

Ten- to 14-year clinical followup of the cementless Natural Knee system.

Of 300 consecutive knees (238 patients) that had undergone arthroplasty with the cementless Natural Knee prosthesis from 1985 to 1989, 176 knees (141 patients) were available for followup at an average of 12 +/- 1 years after the operation. Knee function was improved significantly. Modified Hospital for Special Surgery knee scores improved from 59.1 +/- 13.2 points preoperatively to 97.8 +/- 4.7 points at last followup. At last followup, knee range of motion averaged 0 degrees +/- 2 degrees to 120 degrees +/- 10 degrees. Implant survival was 93.4% (including infection and simple polyethylene exchanges) and 95.1% (excluding infection and simple polyethylene exchanges) at 10 years when applying the Kaplan-Meier survival analysis, using loose components, revision, or both as failure criteria. Besides the three revisions for infection, only two femoral and one tibial component required revision. The patellar component survivorship at 10 years was 95.1%. All patellar revisions were attributed to edge wear. Subsequent operative and design changes, including patellar component medialization and countersinking, have decreased the incidence of patellar revision. The long-term results of this cementless knee system compare favorably with those of cemented systems. The Natural Knee design has provided excellent and predictable long-term clinical results in the current series of active patients.     

Posterior stabilized prosthesis. Results after follow-up of nine to twelve years.

We reviewed, nine to twelve years postoperatively, the records on an original cohort of 289 arthroplasties (218 patients) in which a posterior stabilized knee prosthesis with an all-polyethylene tibial component had been inserted at The Hospital for Special Surgery. One hundred and eighty intact prostheses in 139 patients were available for this analysis. Fourteen knees in fourteen patients had had a revision procedure. Five of these fourteen patients had had a bilateral arthroplasty, but only one knee of each of the five patients had been revised. Forty-eight of the patients (sixty-six knees) had died less than nine years after the operation. Twenty-nine other knees (twenty-two patients) had been lost to follow-up before a nine-year evaluation could be performed. Considering all 194 knees (including the fourteen that had been revised), the result with the system of The Hospital for Special Surgery was excellent for 117 knees (61 per cent), good for fifty-one (26 per cent), fair for twelve (6 per cent), and poor for the fourteen knees (7 per cent) that had been revised. The 180 knees in which the prosthesis was intact were also rated with the new scoring system of The Knee Society: the average postoperative knee score was 92 points (range, 35 to 100 points), and the average score for function was 66 points (range, 0 to 100 points). Survivorship analysis showed that the average annual rate of failure was 0.4 per cent and that the over-all rate of success at thirteen years was 94 per cent.(ABSTRACT TRUNCATED AT 250 WORDS)     

Revision total knee arthroplasty with the Total Condylar III system in inflammatory arthritis

We report a consecutive series of 16 revision total knee arthroplasties using the Total Condylar III system in 14 patients with inflammatory arthritis which were performed between 1994 and 2000. There were 11 women and three men with a mean age of 59 years (36 to 78). The patients were followed up for 74 months (44 to 122). The mean pre-operative Knee Society score of 37 points (0 to 77) improved to 88 (61 to 100) at follow-up (t-test, p < 0.001) indicating very good overall results. The mean range of flexion improved from 62 degrees (0 degrees to 120 degrees) to 98 degrees (0 degrees to 145 degrees) (t-test, p < 0.05) allowing the patients to stand from a sitting position. The mean Knee Society pain score improved from 22 (10 to 45) to 44 (20 to 50) (t-test, p < 0.05). No knee had definite loosening, although five showed asymptomatic radiolucent lines. Complications were seen in three cases, comprising patellar pain, patellar fracture and infection. These results suggest that the Total Condylar III system can be used successfully in revision total knee arthroplasty in inflammatory arthritis.     

Total knee arthroplasty using cruciate-retaining kinematic condylar prosthesis.

The purpose of the current study was to evaluate the long-term results of the Kinematic I condylar prosthesis with retention of the posterior cruciate ligament. One hundred sixty-eight total knee arthroplasties in 118 patients (mean age, 65.2 years; range, 21-88 years) were inserted with cement, an all-polyethylene patella, metal-backed tibia, and posterior cruciate ligament retention. Sixty-one patients (86 knees) died, one patient had an above-knee amputation, and three patients (five knees) were lost to followup; therefore, 66 knees (excluding revisions) in 50 patients were available for followup at a mean of 15.7 +/- 1.1 years (range, 14-20 years). Of the entire cohort of 168 knees, 13 have been revised: one for medial femoral condyle fracture, one for tibiofemoral instability, one for femoral and two for tibial component aseptic loosening, four for tibial polyethylene wear, and four for patellar component aseptic loosening. The 15-year survivorship free of any component revision excluding infections was 88.7% (confidence interval, 82%-95%). The 15-year survivorship free of radiographic loosening and/or revision of any component was 85.1% (confidence interval, 78%-92%). The current study shows good function and survivorship of the posterior cruciate-sparing Kinematic I condylar prosthesis at a mean of 15.7 +/- 1.1 years.     

Posterior cruciate ligament-retaining total knee arthroplasty in patients with rheumatoid arthritis

BACKGROUND: Although initial reports on posterior cruciate ligament-retaining total knee arthroplasty in patients with rheumatoid arthritis have been encouraging, a high rate of late instability necessitating revision has been reported recently. The purpose of the present prospective study was to analyze the results of posterior cruciate ligament-retaining total knee arthroplasty in patients with rheumatoid arthritis. METHODS: Seventy-two posterior cruciate ligament-retaining total knee arthroplasties in fifty-one patients with rheumatoid arthritis were studied prospectively. All procedures were performed with the Miller-Galante I prosthesis. Eighteen patients (twenty-four knees) died before the eight-year follow-up and one patient (two knees) was lost to follow-up, leaving forty-six knees (thirty-two patients) for review. These forty-six knees were evaluated clinically (with particular attention to posterior instability) and radiographically at annual intervals for a mean of 10.5 years (range, eight to fourteen years). RESULTS: Forty-four (95%) of forty-six knees had a good or excellent result at a mean of 10.5 years. However, nine (13%) of the original seventy-two knees had revision of the implant, with six of the revisions performed because of failure of a metal-backed patellar component. The rate of survival at ten years was 93% 4% with femoral or tibial revision for any reason as the end point and 81% 5% with any reoperation as the end point. There was no aseptic loosening in any knee. Posterior instability was identified clinically and/or radiographically in two (2.8%) of the original seventy-two knees; both unstable knees were in the same patient. CONCLUSION: Posterior cruciate ligament-retaining total knee arthroplasty yielded satisfactory clinical and radiographic results in patients with rheumatoid arthritis at intermediate-term follow-up (mean, 10.5 years). Therefore, we believe that it remains an excellent treatment option for these patients.     

Unicompartmental knee arthroplasty. Clinical experience at 6- to 10-year followup.

Sixty-two consecutive cemented modular unicompartmental knee arthroplasties in 51 patients were studied prospectively. At surgery, the other compartments had at most Grade 2 chondromalacia. The average age of the patients at arthroplasty was 68 years (range, 51-84 years). One patient was lost to followup and 10 died with less than 6 years followup. The average followup of the remaining 51 knees was 7.5 years (range, 6-10 years). The preoperative Hospital for Special Surgery knee score of 55 points (range, 30-79 points) improved to 92 points (range, 60-100 points) at followup; 78% (40 knees) had excellent and 20% (10 knees) had good results. The mean range of motion at followup was 120 degrees with 26 knees (51%) having range of motion greater than 120 degrees. One patient underwent revision surgery for retained cement, one patient underwent knee manipulation, and one patient underwent revision surgery at 7 years for opposite compartment degeneration and pain. Radiographically, 26 knees (51%) had at least one partial radiolucency. There were no complete femoral radiolucencies, but there were three complete tibial radiolucencies, all less than 2 mm. No component was loose as seen on radiographs. At final followup, five of the opposite compartments (10%) and three of the patellofemoral joints (6%) had some progressive radiographic joint space loss; this was less than a 25% loss in all but one knee component that was revised. At 6- to 10-years followup, cemented unicompartmental knee arthroplasty yielded excellent clinical and radiographic results. The 10-year survival using radiographic loosening or revision as the end point was 98%. Using stringent selection criteria, unicompartmental knee replacement can yield excellent results and represents a superb alternative to total knee replacement.