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Unicompartmental knee arthroplasty (UKA) is an effective alternative to total knee arthroplasty (TKA) for the management of unicondylar osteoarthritis. Historical contraindications limit patients' eligibility for UKA. However, recent reports have suggested that some contraindications may not be absolute. This study evaluates preoperative flexion contracture with regard to UKA.This study was a retrospective review of 53 patients with preoperative flexion contracture between 11° and 20° who underwent fixed-bearing UKA and a matched cohort of 53 patients who underwent cruciate-retaining TKA.Preoperatively, the average flexion contracture was 13.8° in the UKA group and 14.1° in the TKA group (P = 0.42). Mean preoperative motion was greater in the patients treated with UKA (106°) than in those treated with TKA (97°; P0.001). Postoperatively, patients who underwent UKA had greater motion than patients who underwent TKA had (121° versus 113°; P0.01). Residual flexion contracture was greater in the UKA group (4.1°) than in the TKA group (2.1°; P = 0.02). The two groups demonstrated similar improvements in Knee Society clinical scores (P = 0.32). However, patients treated with UKA demonstrated higher Knee Society functional scores, compared with patients treated with TKA (86 versus 75; P = 0.03).Although residual flexion contracture was worse after UKA, this group had similar clinical improvement, greater postoperative motion, and greater function scores, compared with the matched TKA group. Preoperative flexion contracture5° may not be an absolute contraindication to UKA.The contraindications to UKA regarding flexion contracture may not be as absolute as previously thought. Larger, prospective studies are needed to generalize these findings to a wider population.

Background Unicompartmental knee arthroplasty (UKA) lends itself to the outpatient surgical setting. Prior literature has established a low rate of readmission and post-operative complications when performed in a hospital outpatient setting (HOP). To our knowledge, there have been no studies comparing complications of UKA performed at an ambulatory surgery center (ASC) and those in a HOP. Methods We retrospectively reviewed all patients who underwent outpatient UKA by a single surgeon from 2012 to 2016. In all 569 outpatient UKAs were performed: 288 in the ASC group and 281 in the HOP group. We compared the groups with regard to all complications within the first 90 days after surgery. Results Thirty minor and major complications occurred within 90 days (5.3%). There was no difference in the overall complication rate between groups (ASC 12, 4.2%; HOP 18, 6.4%) ( P = .26). Day of surgery admission occurred once in the HOP group (0.4%) and did not occur in the ASC group ( P = .49). There was 1 visit to the emergency department (ED) P = 1.0). ED visits occurred within 7 days in 3 ASC cases (1.0%) and 4 HOP cases (1.4%) ( P = .72). Re-admissions in the first 90 days occurred in 5 ASC cases (1.7%) and 8 HOP cases (2.8%) ( P = .41). Conclusion UKA at an ASC has a low early postoperative complication rate without increased risk of re-admission or ED evaluation when compared to UKAs performed at a HOP.

Minimally invasive unicondylar arthroplasty (UKA) continues to gain popularity for the management of patients with degenerative arthritis limited to one compartment of the knee. In this study, we examine a series of 517 fixed-bearing, cemented unicompartmental knee components implanted in patients to manage degenerative arthritis in the medial compartment of their knee. All UKAs were performed at a single institution using the same fixed-bearing design. In this study we sought to examine the survivorship of the UKA components and the mechanisms of failure for the knees that were revised. The survivorship and revision rate with this implant were similar to those found in other published reports of fixed-bearing unicompartmental arthroplasties performed through minimally invasive surgical techniques.

This study examined 445 consecutive minimally invasive unicompartmental knee arthroplasties (UKAs) from one institution to determine whether revision and reoperation rates would decrease as the number of cases performed increased, indicating the presence of a learning curve with this procedure. At a mean of 3.25 years, 26 knees required revision yielding an overall revision rate of 5.8%; survivorship at 2 years with revision as an end point was 96% +/- 1.7%. Both revisions and reoperations decreased over time but not significantly. For the first half of UKA cases performed vs the second half, revision rates fell from 5.0% to 2.5%, and reoperation rates fell from 8.1% to 5.4%. These data demonstrate that despite modifications made to improve surgical technique across time, a substantial complication rate with this procedure persists.

Background: Tibial bone loss is frequently encountered at the time of revision total knee arthroplasty, and the outcome of the revision often depends on the management of this bone deficiency. We examined the clinical and radiographic outcomes of a series of revision total knee arthroplasties in which a structural allograft had been used to reconstruct a tibial bone defect encountered at the time of the revision procedure. Methods: From January 1985 through September 1999, one surgeon performed revision arthroplasty in forty-nine knees (forty-seven patients) with a severe tibial bone defect. The reasons for the revisions included polyethylene wear and osteolysis in twenty-four knees, aseptic loosening in seventeen knees, infection in five knees, and failure for another reason for three knees. Structural allograft was used alone in thirty-five knees and in conjunction with a tibial augment in fourteen knees. The mean age of the patients at the time of the revision arthroplasty with the allograft was sixty-seven years. The patients were assessed clinically with use of the Knee Society score and radiographically. Results: The status of the implant was known for forty-six of the forty-nine knees in this study. It was unknown for one patient (one knee) who was lost to follow-up and for two patients (two knees) who died less than five years postoperatively. Four revision procedures in four patients failed and required a reoperation. Two of the failures were due to infection. At a mean of ninety-seven months postoperatively, the mean Knee Society clinical score was 84 points for the knees that had not had a reoperation due to failure. The mean arc of motion improved from 87° preoperatively to 103° at the most recent follow-up evaluation. Histological evaluation of specimens retrieved at two autopsies demonstrated graft union to host bone. Conclusions: A structural allograft provides a stable and durable reconstruction of a tibial bone deficiency. At a mean of ninety-five months postoperatively, we found no instance of graft collapse or aseptic loosening associated with the structural allograft. We recommend the use of a structural allograft for the management of severe tibial bone deficiency at the time of revision total knee arthroplasty. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Osteolysis induced by wear debris of ultra-high-molecular-weight polyethylene has emerged as a significant problem after total knee arthroplasty. The generation of polyethylene wear and the development of osteolysis around total knee arthroplasty are caused by a combination of patient, implant, and surgical factors. Activity level over time may be the most important patient factor affecting the loads placed on a total knee replacement, but it is the most difficult to manage. Multiple factors related to the manufacturing of the polyethylene implant influence the extent of wear, and surgeons should be cautious in considering enhanced polyethylenes pending results of further investigations. The optimal design of the articular bearing surface remains controversial but needs to be considered with respect to the stresses imparted on component-bone and modular tibial backside interfaces. Surgical factors, including restoration of alignment and ligament balance, are important for long-term durability of the implant. Methods of measuring the wear of total knee implants are still evolving. Thus, when confronted with a worn total knee implant and developing osteolysis, the surgeon should consider each of these factors in selecting the best management option to eliminate the source of debris and minimize the potential for wear and osteolysis following revision.

Several reports document high failure rates of metal-backed patellar components, but few report the outcome of revising these components to all-polyethylene, cemented implants. At a mean 87.2-month follow-up, we describe a series of 36 patients (40 knees) who underwent isolated metal-backed patellar revision to a cemented, all-polyethylene patellar component. After the patellar revision, 5 patients (6 knees) underwent additional surgery, but no patellar components required revision. The additional surgeries were performed at an average of 77.6 months after patellar revision and included 3 tibial insert exchanges for polyethylene wear, 2 revisions of femoral and tibial components for osteolysis, and 1 realignment procedure for recurrent subluxation of the patella. We conclude that revision of a failed metal-backed patellar component to a cemented, all-polyethylene patella is a durable, successful procedure.

Sixty-five consecutive Coordinate (DePuy, Warsaw, Ind) revision total knee arthroplasties were eligible for minimum 5-year follow-up. Nine patients died and 2 patients were lost. Therefore, 54 knees (51 patients) had a known outcome. Nine knees failed and required either revision or component removal. Eight additional knees were considered clinical failures. Despite the use of metallic augmentation in 89% of the knees, large structural allografts were required in 48% of the knees. Revisions with bone loss that required bulk allograft failed less often (19.2%) than revisions managed without bulk allografts (42.9%). Of 24 knees originally revised for osteolysis/polyethylene wear, only 1 required rerevision for the same mechanism of failure. Modular augments did not effectively address the bone loss and instability encountered in many instances at revision surgery. Survivorship of this implant was 79.4% ± 13.7% at 8 years.

Controversy exists about whether a functional anterior cruciate ligament is necessary to achieve success with unicompartmental knee arthroplasty. When the anterior cruciate ligament was deficient, higher failure rates were reported with mobile-bearing implants and with the Lotus implant, a relatively flat, fixed-bearing component. Most failures were secondary to wear. In contrast, the absence of an anterior cruciate ligament did not lead to failure with the St. Georg and Marmor implants. Theoretically, an absent anterior cruciate ligament would increase the sliding motion that caused accelerated polyethylene wear in laboratory studies. Hypothetically, such motion could lead to accelerated wear of unicompartmental arthroplasty in an ACL deficient knee. Currently, unicompartmental knee arthroplasties should not be done in patients with symptoms of anterior cruciate ligament instability and should judiciously be done in older patients without a functional anterior cruciate ligament but with no symptoms of instability.

Background: We observed a complication of posterior stabilized total knee arthroplasty involving hypertrophy of tissue proximal to the patella associated with pain during active knee extension from 90° of flexion. The purpose of this paper was to describe synovial entrapment and to determine if design features of the prosthesis predispose patients to the complication. Methods: Between April 1990 and June 1999, we performed 459 consecutive posterior stabilized primary total knee arthroplasties using three prosthetic designs with different femoral intercondylar geometries. We identified twenty-six patients (twenty-seven knees) in whom arthroscopic debridement of the knee or open arthrotomy with debridement of the knee had been subsequently performed because of a diagnosis of synovial entrapment. We reviewed the records of these patients to identify the knee components that had been used and the symptoms and conditions that necessitated additional treatment. Results: Symptoms (grating, crepitation, and pain with active knee extension from 90°) necessitating subsequent debridement occurred in 13.5% (nineteen) of 141 knees treated with the Anatomic Modular Knee-Congruency implant, 3.8% (eight) of 212 treated with the Anatomic Modular Knee-Posterior Stabilized implant, and none of the 106 treated with the Press Fit Condylar Sigma-Posterior Stabilized implant. All patients had difficulty rising from a chair and climbing stairs; however, none had symptoms when standing or walking. No patient had a patellar clunk. The symptoms occurred at a mean of seven months after the arthroplasty in the patients with an Anatomic Modular Knee-Congruency implant and at a mean of twenty months after the arthroplasty in those with an Anatomic Modular Knee-Posterior Stabilized implant. Debridement of the frond-like hypertrophic synovial tissue at the distal aspect of the quadriceps tendon alleviated symptoms in all patients. No nodules were identified during the arthroscopy. Conclusions: Synovial entrapment is characterized by hypertrophic synovial tissue at the superior pole of the patella. Use of a posterior stabilized femoral component with a proximally positioned or wide femoral box is more likely to result in this complication.

In the current study, 27 consecutive total knee arthroplasties in 21 patients were assessed. All patients had a preoperative range of motion of less than 50 degrees, severe debilitation, and a minimum clinical and radiographic followup of 2 years (mean, 6 years; range, 2.3-11.8 years). The mean preoperative arc of motion was 30 degrees (range, 0 degrees -50 degrees) and improved to a mean 74 degrees (range, 15 degrees -110 degrees) postoperatively. Preoperative flexion contracture was corrected from a mean 28 degrees (range, 0 degrees -60 degrees) to a mean postoperative flexion contracture of 4.4 degrees (range, -5 degrees -30 degrees). In this series, the overall complication rate was 41% and the revision rate was 18.5%. The clinical significance of this study is that patients with stiff knees who are debilitated severely can have an improved quality of life after total knee arthroplasty, reflected by an increased walking tolerance, increased functional abilities, and decrease in pain, but in association with a high risk of complications and subsequent revisions.

Little information has been published on the salvage of failed unicompartmental knee arthroplasty. The current authors examined the failure mechanisms, complexity of surgery, and complications in such revisions. Of 39 consecutive unicompartmental knee revisions, two patients died within 2 years of surgery, four had inadequate followup, and one was excluded because of infection before revision. Therefore, 30 patients (32 knees) were followed up a mean 53 months. The patients were a mean age of 59 years at the time of unicompartmental knee arthroplasty and were predominantly male (60%). Revisions were done 9 to 204 months after the unicompartmental knee arthroplasty. The predominant failure mechanism was polyethylene wear; however, nine failed because of loosening. The mean polyethylene thickness of the failed arthroplasties was 7.3 mm. Revision procedures were straightforward. Ten patients required local autograft but no allografts were used. Primary femoral components were used in all patients; 25 were cruciate-retaining. Fourteen patients had stemmed tibial components; eight had wedge augments. The mean range of motion after revision was 111 degrees. Six patients had complications not requiring intervention. Three patients had rerevision surgery for polyethylene wear at 76, 77, and 102 months, respectively, two of whom required polyethylene insert and patellar component revision. The third patient also required tibial component revision for osteolysis. Although this is a small series, the simplicity of the procedure and the complications encountered compare favorably with those of total knee revision.

We reviewed 139 consecutive femoral or tibial revision knee arthroplasties to determine if the outcome of revision knee arthroplasty using revision implant systems was superior to revisions using primary implant systems. Group 1 (n = 42) consisted of revisions performed with implants designed for primary total knee arthroplasty. Group 2 (n = 42) consisted of revisions performed with modified primary components. Group 3 (n = 55) consisted of revisions performed with components specifically designed for revision arthroplasty. The implant status was known in 123 of 139 knees at a mean follow-up of 7 years (range, 5-12 years). The implant-related failure rate, defined as reoperation requiring component revision or removal, was 26% for group 1, 14% for group 2, and 6% for group 3 (P.05). Revision implants exhibited superior performance and durability despite their use in more difficult reconstructions. The improved longevity of revision implants justifies the evolution of modular revision components.

Preoperative radiographic planning for revision total knee arthroplasty begins with obtaining excellent quality AP and lateral radiographs that permit: 1. Evaluation of the extent of bone loss in the metaphyseal region of the femur and tibia. 2. Full visualization of the patient's intramedullary canal for determining appropriate stem size and length. The surgeon should then determine the appropriate bone defect classification, keeping in mind the provisions needed to address Type 2 and 3 defects. These provisions include any augments or allografts, stemmed components, and the degree of component constraint needed in the patient's revision surgery. Through preoperative templating, the surgeon can determine whether a particular implant system provides the options necessary to achieve an optimal surgical result. Whenever templating leaves unanswered questions regarding the extent of bone damage or the degree of knee instability, the surgeon must prepare for the worst case scenario to ensure that the appropriate components and graft material are made available.

The unique characteristics that predispose patients to periprosthetic fractures make treatment difficult and unpredictable. Severe osteoporosis makes fracture fixation precarious. The typical elderly and debilitated patient must be mobilized rapidly to avoid medical complications brought on by prolonged bed rest and inactivity. However, walking with protected weight-bearing often is impossible because of multiple-joint involvement, neurological disorders, and systemic illness. In most instances, early and definitive treatment is preferable to a prolonged period of bed rest and inactivity. Periprosthetic fractures may occur intraoperatively or postoperatively. The best treatment technique depends on whether the fracture is identified intraoperatively or postoperatively as well as on its location and severity. Common fracture-repair techniques, such as those involving use of a plate and screws, intramedullary rods, and external fixators, have been associated with variable rates of success. This paper examines the role of different techniques for management of the fracture and revision of the component in the treatment of periprosthetic fractures. Periprosthetic fractures that occur during a knee-replacement arthroplasty are rarely as challenging to treat as fractures that occur in the postoperative period. Most intraoperative fractures are neither displaced nor comminuted, the stability of the components is rarely altered, and the fractures are not associated with soft-tissue trauma. Treatment techniques that permit the patient to exercise safely during the early postoperative period should lead to an optimum clinical outcome. Usually, screws are adequate for stabilizing the fracture, and the patient may safely proceed with an unaltered rehabilitation protocol. ### Femoral Fractures When a fracture that splits the condyles occurs while the surgeon is making the box cut for a posterior stabilized component (Fig. 1-A), a transcondylar cancellous-bone screw can be used to stabilize the fracture. One screw usually is sufficient because the cement and the femoral component provide additional stability. If the metaphyseal bone is soft, a washer …

Questionnaires are marginally useful for objectively measuring function after knee arthroplasty. The Functional Assessment (FA) test is an easily administered, timed test of a person's ability to stand, walk and ascend/descend stairs that would be useful for quantifying a patient's function after knee arthroplasty. Four hundred forty-five individuals were included in the study: 313 without lower extremity arthritis or neurologic disease and 132 with advanced degenerative arthritis prior to knee arthroplasty. As expected, the test times were longer for individuals afflicted with knee arthritis. Arthroplasty patients were tested pre- and postoperatively to determine if their FA test time improved. The FA test takes less than a minute and is practical for use in the clinical setting as a simple means of quantifying function before and after knee arthroplasty.

Historically, a functional ACL has been a prerequisite for patients undergoing unicondylar knee arthroplasty (UKA). However, this premise has not been rigorously tested.We compared (1) the survivorship free from revision and (2) the failure mechanisms of UKAs in ACL-deficient knees and UKAs in ACL-intact knees performed over the same time interval.Between November 2000 and July 2008, a fixed bearing UKA was performed in 72 patients (81 knees) with intraoperatively confirmed ACL deficiency. Five patients (five knees) with preoperative instability underwent ACL reconstruction and were excluded from analysis. Of the remaining 67 patients (76 knees) without preoperative instability, implant status was known for 68 UKAs in 60 patients. Survivorship and failure mechanisms for these knees were compared to those of 706 UKAs in ACL-intact knees performed during the same time interval by the same surgeon using the same implant system. Minimum followup for the ACL-deficient group was 2.9 years (mean, 6 years; range, 2.9-10 years).Revision rates between UKAs with and without intact ACLs were similar in the absence of clinical instability (p = 0.58). Six-year UKA survivorship was 94% (95% CI: 88%-100%) in ACL-deficient knees and 93% (95% CI: 91%-96%) in ACL-intact knees (p = 0.89). Five knees (7%) in the ACL-deficient group were revised: disease progression (two), loose tibia (one), persistent pain (one), and revised elsewhere/reason unknown (one). Thirty-six knees in the ACL-intact group underwent revision (5%): aseptic loosening (13), revised elsewhere/reason unknown (11), disease progression (three), tibial subsidence/fracture (four), infection (three), pain (one), and lateral compartment overload (one).At 6 years, deficiency of the ACL in patients without clinical knee instability did not impact the survivorship of UKAs compared to UKAs performed in knees with intact ACLs.

Although the host tissue response to debris is rarely symptomatic, the clinical manifestations of implant wear are profound. Even the most experienced orthopedic surgeon can be challenged in managing this sometimes silent disease.

Instability is one of the leading causes of clinical failure after total knee arthroplasty. Instability can be categorized according to three basic patterns: AP or flexion space instability, varus/valgus or extension space instability, and global instability. Surgical options for treating instability include polyethylene exchange of a modular component, revision to a more constrained component, or revision to a hinged component. The results achieved with these surgical options vary for each type of instability. In general, the use of more constrained components to manage unstable knees is favored.

Osteolysis is an emerging problem in patients who undergo total hip arthroplasty and total knee arthroplasty (TKA). Before the introduction of modular components, osteolysis was not as prevalent in patients who underwent TKA. Although polyethylene wear and the generation of small-particle debris were linked to the presence of osteolysis in patients who have undergone total hip arthroplasty, the fatigue-type wear and larger wear particles often seen with TKA were not thought to invoke the cellular response that causes osteolysis. Despite the lack of an identifiable cause for the osteolysis, the number of knees that developed lesions continued to increase. Therefore, modular components were examined to determine whether this innovation in TKA was actually contributing to the manifestation of osteolysis.

Several reports document high failure rates of metal-backed patellar components, but few report the outcome of revising these components to all-polyethylene, cemented implants. At a mean 87.2-month follow-up, we describe a series of 36 patients (40 knees) who underwent isolated metal-backed patellar revision to a cemented, all-polyethylene patellar component. After the patellar revision, 5 patients (6 knees) underwent additional surgery, but no patellar components required revision. The additional surgeries were performed at an average of 77.6 months after patellar revision and included 3 tibial insert exchanges for polyethylene wear, 2 revisions of femoral and tibial components for osteolysis, and 1 realignment procedure for recurrent subluxation of the patella. We conclude that revision of a failed metal-backed patellar component to a cemented, all-polyethylene patella is a durable, successful procedure.

We observed a complication of posterior stabilized total knee arthroplasty involving hypertrophy of tissue proximal to the patella associated with pain during active knee extension from 90 degrees of flexion. The purpose of this paper was to describe synovial entrapment and to determine if design features of the prosthesis predispose patients to the complication.Between April 1990 and June 1999, we performed 459 consecutive posterior stabilized primary total knee arthroplasties using three prosthetic designs with different femoral intercondylar geometries. We identified twenty-six patients (twenty-seven knees) in whom arthroscopic débridement of the knee or open arthrotomy with débridement of the knee had been subsequently performed because of a diagnosis of synovial entrapment. We reviewed the records of these patients to identify the knee components that had been used and the symptoms and conditions that necessitated additional treatment.Symptoms (grating, crepitation, and pain with active knee extension from 90 degrees) necessitating subsequent débridement occurred in 13.5% (nineteen) of 141 knees treated with the Anatomic Modular Knee-Congruency implant, 3.8% (eight) of 212 treated with the Anatomic Modular Knee-Posterior Stabilized implant, and none of the 106 treated with the Press Fit Condylar Sigma-Posterior Stabilized implant. All patients had difficulty rising from a chair and climbing stairs; however, none had symptoms when standing or walking. No patient had a patellar clunk. The symptoms occurred at a mean of seven months after the arthroplasty in the patients with an Anatomic Modular Knee-Congruency implant and at a mean of twenty months after the arthroplasty in those with an Anatomic Modular Knee-Posterior Stabilized implant. Débridement of the frond-like hypertrophic synovial tissue at the distal aspect of the quadriceps tendon alleviated symptoms in all patients. No nodules were identified during the arthroscopy.Synovial entrapment is characterized by hypertrophic synovial tissue at the superior pole of the patella. Use of a posterior stabilized femoral component with a proximally positioned or wide femoral box is more likely to result in this complication.

Background: The mechanical toughness of polyethylene that has been sterilized by gamma irradiation in air decreases after a long shelf life. The purpose of the present study is to report the high failure rate after unicondylar knee replacements performed with polyethylene bearings that had been sterilized with gamma irradiation in air and implanted after a shelf life of ≤4.4 years. Methods: Between December 1997 and January 2000, seventy-five unicondylar knee replacements were performed in sixty-two patients. All patients were followed both clinically and radiographically. A revision operation was offered when the patient had pain, swelling, and radiographic evidence of rapid polyethylene wear. The effect of aging of the polyethylene during storage was evaluated by dividing the knees into three groups on the basis of shelf life and comparing them with regard to the rate of revision and the observed wear of the polyethylene. Four retrieved components were examined for the presence of oxidation. Results: At a mean of eighteen months after the arthroplasty, thirty knees had been revised and seven were scheduled for revision. The rate of polyethylene wear increased as the shelf life increased. There was a significant inverse linear correlation between the shelf life of the polyethylene and the time to revision (p < 0.01, r2 = 0.64). All retrieved components had greater-than-expected wear with pitting and delamination of the surface. Seven components had fractured, and ten had both fractured and fragmented. Analysis of four components confirmed severe oxidation of the polyethylene. Conclusion: The present study demonstrated early, severe wear of tibial polyethylene bearings that had been sterilized by gamma irradiation in air and stored for ≤4.4 years. This risk can be minimized by ensuring that implants have not been sterilized with gamma irradiation in air and stored for several years.

The rate of lateral retinacular releases in 2 groups of patients who underwent knee surgery performed by the senior author is compared and the factors that contribute to these differing rates are discussed. The first group of subjects consists of 88 patients who had total knee arthroplasties performed with a standard medial parapatellar approach between August 1987 and August 1988. The second group is comprised of 88 patients who had total knee arthroplasties through a midvastus surgical arthrotomy that splits the fibers of the vastus medialis muscle. This method is used by the senior author for all primary total knee arthroplasties. Lateral retinacular releases were performed in 50% of the cases in the medial parapatellar group versus only 3% of the cases in the midvastus group. Patellofemoral instability occurs as a consequence of incising the quadriceps tendon in the medial parapatellar approach and results in the need to perform lateral retinacular releases. The reduction in lateral retinacular releases is attributed to the fact that the midvastus approach leaves the connection of the vastus medialis to the quadriceps tendon intact.

The clinical results of using medial epicondylar osteotomies to correct varus deformities in total knee arthroplasties were investigated. Unlike the traditional method of subperiosteal stripping of tibial ligaments, this alternative does not damage ligaments. Between 1991 and 1996, the senior author performed medial epicondylar osteotomies in 80 patients (93 knees) with primary total knee arthroplasty; of these, 60 patients (70 knees) were available for 2- to 4-year followup. At followup, no patients reported knee instability. Mean varus and valgus stability measured 14.2 points (Knee Society scale, 0-15 points). The Knee Society clinical score was 93 points, compared with a preoperative score of 42 points. The mean range of motion at followup was 111 degrees, compared with a preoperative mean of 101 degrees. The postoperative tibiofemoral angle on full limb radiographs taken with the patient weightbearing averaged 7 degrees valgus, compared with an average 6 degrees varus preoperative angle. Ninety-five percent of the patients were satisfied and reported less pain and improved knee function. Bone union occurred in 54% of the knees and fibrous union occurred in 46%. Focal tenderness, restricted motion, or other symptoms were not associated with fibrous union. The results show that epicondylar osteotomy for varus knee deformity provides excellent patient satisfaction, knee stability, motion, and deformity correction.

The outcome of 186 consecutive total knee arthroplasties performed with the Anatomic Modular Knee is reported. One hundred forty-two knees had followup of 4 to 10 years (mean, 6.9 years). Two knees required revision of all components, one because of infection and the other for instability. Seven patients underwent exchange of the modular tibial polyethylene insert at an average of 84 months postoperatively. The mean age of these seven patients at primary arthroplasty was 54 years. No implant showed clinical or radiographic evidence of loosening and there were no complications related to patellofemoral articulation. The revision rate of the femoral, tibial, and patellar components was two of 142 or 1.4%. The revision rate including exchange of the polyethylene insert was nine of 142 or 6.3%. This minimally constrained posterior cruciate retaining modular design performed well at intermediate followup. The absence of patellofemoral complications and aseptic loosening was notable. Wear related phenomena were the most common indications for reoperation and these occurred in younger, active individuals with relatively thin polyethylene bearings. The relative value of modular tibial inserts and the outcome of isolated polyethylene exchanges warrant additional study.