Four-Year Outcomes of Cementless Versus Cemented Fixation of a Newly Introduced Total Knee Arthroplasty Design.

BACKGROUND: Aseptic loosening continues to be a major cause of failure of total knee arthroplasty (TKA). Although cemented fixation remains the gold standard, there is renewed interest in cementless fixation as a means of decreasing this risk via biologic fixation. The purpose of this study was to evaluate the clinical outcomes of cemented and cementless versions of a newly introduced TKA design at an average of 4 years postoperatively. MATERIALS AND METHODS: This was a retrospective case-control study of 100 primary TKAs comparing cementless vs cemented TKAs using the same cruciate-retaining implant design (ATTUNE Knee System; DePuy Synthes). Fifty patients undergoing cementless TKA with a mean age of 60.8 years (range, 48-71 years) and body mass index (BMI) of 31.6 kg/m2 (range, 23.7-41.9 kg/m2) were matched to 50 patients undergoing primary cemented TKA with a mean age of 62.7 years (range, 51-73 years) and BMI of 30.1 kg/m2 (range, 24.6-43.9 kg/m2). The mean follow-up was 4.2 years (range, 4.0-4.4 years) in the cementless group and 7.6 years (range, 7.5-7.7 years) in the cemented group. Complications, clinical outcomes using the Knee Society Score (KSS), and radiographic analyses were evaluated at final follow-up. Student's t tests were used for statistical analyses. RESULTS: There was no statistical difference in age, BMI, and preoperative KSS between the two groups (P=.12, P=.15, and P=.55, respectively). There were no complications or reoperations in either cohort. There were no statistical differences in range of motion and total KSS at final follow-up between the two groups. Final total KSS had a mean of 91.1 for the cementless group and 93.7 for the cemented group. There was no radiographic evidence of component subsidence or loosening in either cohort. CONCLUSION: When compared with its cemented counterpart, the newly introduced cementless TKA design had similar excellent clinical improvements and radiologic results at an average of 4 years of follow-up. [Orthopedics. 2024;47(3):161-166.].

Unicondylar Knee Arthroplasty Made Simple.

Unicompartmental knee arthroplasty (UKA) has become an increasingly used procedure for patients with unicompartmental knee osteoarthritis. The success of UKA relies on appropriate patient selection and patient optimization before surgery is performed. Improved prosthesis design and surgical techniques for medial and lateral and fixed and mobile bearing UKA have also contributed to improved knee biomechanics, faster recovery, and improved outcomes. Indications, factors affecting patient selection, the role of limb alignment, and the surgical pearls for fixed and mobile bearing and medial and lateral UKA are important topics for discussion.

Hot Topics and Current Controversies in Total Knee Arthroplasty.

Total knee arthroplasty continues to evolve. It is important to review some of the current controversies and hot topics in arthroplasty. Optimal knee alignment strategy is now just a matter of debate. Mechanical, kinematic, and functional alignment and the role of robotics in achieving optimum alignment are important topics, along with fixation and outpatient knee arthroplasty.

The natural history of radiolucencies following cemented unicompartmental knee arthroplasty at 7 years.

INTRODUCTION: Radiolucent lines (RLLs) following unicompartmental knee arthroplasty (UKA) can be concerning as aseptic loosening remains a cause of failure in UKA. The aim of our study was to report on the history of RLLs surrounding the components in a cemented medial compartment fixed-bearing UKA as well as the long-term functional outcomes in this group of patients. MATERIAL AND METHODS: In this retrospective consecutive case-series, twenty-eight patients (37 knees) were treated with medial, fixed-bearing cemented unicompartmental knee arthroplasty. At average final follow-up of 7.1 years, 36 knees were available for review. Radiographs were taken at six weeks, one year, and final follow up. RLLs were measured using a novel modification to the Knee Society scoring (KSS) system. RESULTS: At six-weeks, we identified RLLs in 26 tibias and two femurs out of 37 total knees. At one-year, four additional tibias and both femurs showed some progression of their radiolucencies but were < 2 mm total. At final follow-up, 31 of the 36 tibias (86.1%) and five of the 36 femurs (13.9%) had any RLLs. On the tibial side, RLLs were most common in medial/lateral and anterior/posterior aspects of the tibial tray with few found centrally. On the femoral side, the posterior femoral cut accounted for the most RLLs of any zone at all time points. KSS averaged 93.8 at final follow-up and none of the patients required revision surgery. CONCLUSION: RLLs are common following cemented, fixed-bearing UKA. Many seem to progress slowly up to one year but not thereafter. There does not appear to be any association between the presence of these radiolucencies and long-term follow-up function in this group of patients.

Poor Patient Follow-up After Metal-on-Metal Total Hip Arthroplasty.

Routine follow-up approximately every 2 to 5 years after total hip arthroplasty (THA) is a common practice. However, although patients are informed of the importance of follow-up, our mean follow-up rate for patients after standard non-metal-on-metal (MOM) THA is only 19%. The US Food and Drug Administration has released several statements on the importance of follow-up every 2 years after MOM THA. With the potential risks of MOM THA apparently widely known, we report on our ability to obtain timely follow-up at 2 separate centers. Two separate centers performed 570 MOM THA procedures between 2002 and 2010. An attempt was made to reach every patient by either telephone or letter to obtain ion levels, radiographs, and examinations. Repeat telephone calls and/or letters to those not reached were made annually. Patients were told of the unique importance of follow-up at each contact. Of the patients, 43% had not been seen within the past 5 years, and only 26% had been seen within the past 2 years. Only 61% had their first measurement of ion levels, and only 30% of patients had a second set of measurement of ion levels. A total of 48 revisions occurred in this group, and 36 patients died. Despite the apparent widespread dissemination of information regarding the potential risks of MOM THA and concerted efforts to contact patients for follow-up, we have been able to achieve a follow-up rate of only 26%. This rate is only marginally better than the mean follow-up for non-MOM THA in our practices. The implications of this poor follow-up are unknown. [Orthopedics. 2022;45(4):e196-e200.].

Average narcotic usage in a group of TKA patients following a modern TKA protocol.

INTRODUCTION: The optimal dosing of post-operative total knee arthroplasty (TKA) narcotics is unclear. We report on the average narcotic usage in a group of patients treated with an identical multimodal pain protocol following TKA. MATERIALS AND METHODS: 49 patients undergoing TKA participated in the survey. Patients with pre-op narcotic use, recent prior total joint arthroplasty or study refusal were excluded. All patients received a spinal anesthetic. No pre-surgery narcotics were given. All received an identical local infiltrative anesthetic combination along with a multimodal pain protocol. Patients were placed into an identical rapid rehab program. Narcotic usage during hospitalization was recorded in morphine equivalent doses (MED). Patients were given a journal to record their daily narcotic utilization. RESULTS: Pre-operative pain scores of the excluded groups had slightly higher but clinically insignificant differences compared to the study group. In the hospital, POD1 study group daily MED averaged 28 (range 0-110). POD2 had an average of 33.6 and POD 3 daily usages averaged 28.6 (range 0-100). By the end of week two, the average daily use was 19.2 and 24% patients were off all narcotics. By the end of week four, the average daily usage was 7.5 and 63% of patients were off all narcotics. By 8 weeks, there were no patients still taking narcotics. KSS averaged 76.9 (range 51-97) at the 6 week visit, and 94.2 at the 3-month visit (range 72-100). SUMMARY: This study documents the average needs of an average TKA patient treated with modern pain protocols. The majority of these patients were off narcotics by week four.

Modern full-component aseptic revision total knee arthroplasties have similar recoveries compared with primary total knee arthroplasty patients when applying an enhanced recovery anaesthetic and analgesic protocol.

AIMS: Enhanced perioperative protocols have significantly improved patient recovery following primary total knee arthroplasty (TKA). Little has been investigated the effectiveness of these protocols for revision TKA (RTKA). We report on a matched group of aseptic revision and primary TKA patients treated with an identical pain and rehabilitation programmes. METHODS: Overall, 40 aseptic full-component RTKA patients were matched (surgical date, age, sex, and body mass index (BMI)) to a group of primary cemented TKA patients. All RTKAs had new uncemented stemmed femoral and tibial components with metaphyseal sleeves. Both groups were treated with an identical postoperative pain protocol. Patients were followed for at least two years. Knee Society Scores (KSS) at six weeks and at final follow-up were recorded for both groups. RESULTS: There was no difference in mean length of stay between the primary TKA (1.2 days (0.83 to 2.08)) and RTKA patients (1.4 days (0.91 to 2.08). Mean oral morphine milligram (mg) equivalent dosing (MED) during the hospitalization was 42 mg/day for the primary TKA and 38 mg/day for the RTKA groups. There were two readmissions: gastrointestinal disturbance (RTKA) and urinary retention (primary TKA). There no were reoperations, wound problems, thromboembolic events or manipulations in either group. Mean overall KSS for the RTKA group was 87.3 (45 to 99) at six-week follow-up and 89.1 (52 to 100) at final follow-up (mean 3.9 years, (3.9 to 9.0)). Mean overall KSS for the primary group was 89.9 (71 to 100) at six-week follow-up and 93.42 (73 to 100) at final follow-up (mean 3.5 years (2.5 to 9.2)). CONCLUSION: An identical pain and rehabilitation protocol used for primary TKA patients can enable certain full-component aseptic RTKA patients to have a similar early functional outcome. Cite this article: Bone Joint J 2020;102-B(6 Supple A):96-100.

The Natural History of Radiolucencies Following Uncemented Total Knee Arthroplasty at 9 Years.

BACKGROUND: Aseptic loosening remains a common cause of failure in total knee arthroplasty (TKA). There is an increased interest in using uncemented TKA to reduce this complication. Radiolucencies (RLs) following uncemented TKA can be concerning. We report on the 9-year history of RLs in patients with uncemented TKA. METHODS: Twenty-one patients (26 knees) were treated with a cruciate-retaining fully porous coated femur/tibia and cemented patella. At final follow-up, 17 patients (22 knees) were available for review. Average follow-up was 9.6 years, average age was 59.1, and average body mass index was 34.1. X-rays were taken at 6 weeks, 1 year, and at final follow-up. RLs were measured using the Knee Society scoring system and read by two separate surgeons. RESULTS: At 6 weeks, we identified RL in all patients on both the tibia and femur. The majority were beneath the tibial tray and femoral chamfer. At 1 year, 4 femurs and 4 tibias showed new RLs (<2 mm) in similar zones. Eighteen femurs and 18 tibias showed fewer or no change in RLs. At final follow-up, no new tibia or femur developed a new RL. In total, 9 of the 22 tibias and 17 of the 22 femurs had remaining RLs, all less than 2 mm and none were progressive or new. Knee Society Score averaged 92.5 (6 weeks), 95.1 (1 year), and 97.3 (final). CONCLUSION: RLs are common following uncemented TKA. Many resolve by 1 year. There does not appear to be any association between the presence of RLs and long-term follow-up function in this group of patients.

What publicly available quality metrics do hip and knee arthroplasty patients care about most when selecting a hospital in Maryland: a discrete choice experiment.

OBJECTIVE: To quantify which publicly reported hospital quality metrics have the greatest impact on a patient's simulated hospital selection for hip or knee arthroplasty. DESIGN: Discrete choice experiment. SETTING: Two university-affiliated orthopaedic clinics in the greater Baltimore area, Maryland, USA. PARTICIPANTS: One hundred and twenty-eight patients who were candidates for total hip or knee arthroplasty. PRIMARY AND SECONDARY OUTCOME MEASURES: The effect and magnitude of acceptable trade-offs between publicly reported hospital quality parameters on patients' decision-making strategies using a Hierarchical Bayes model. RESULTS: Publicly reported information on patient perceptions of attention to alleviation of postoperative pain had the most influence on simulated hospital choice (20.7%), followed by methicillin-resistant Staphylococcus aureus (MRSA) rates (18.8%). The understandability of the discharge instructions was deemed the least important attribute with a relative importance of 6.9%. Stratification of these results by insurance status and duration of pain prior to surgery revealed that patient demographics and clinical presentation affect the decision-making paradigm. CONCLUSIONS: Publicly available information regarding hospital performance is of interest to hip and knee arthroplasty patients. Patients are willing to accept suboptimal understanding of discharge instructions, lower hospital ratings and suboptimal cleanliness in exchange for better postoperative pain management, lower MRSA rates, and lower complication rates.

Ignore the Patella in Revision Total Knee Surgery: A Minimum 5-Year Follow-Up With Patella Component Retention.

BACKGROUND: In the setting of aseptic revision, a common question is: what should be done with the previously resurfaced patella? We report on a series of aseptic revision total knee arthroplasties (RTKA) where one or both components were revised and the patella was not. METHODS: The study group was 147 consecutive RTKA in 137 patients with a mean age of 70.1 ± 9.3 years where the patella was not revised. The average body mass index was 31.0 ± 5.4 kg/m2. Follow-up was a minimum of 5 years (range, 5 to 12 years). At final follow-up, 13 patients died and 2 patients were lost to follow-up leaving 122 patients and 130 knees available for review. Mean time from primary surgery to RTKA was 9.2 ± 5.5 years. Both components were revised in 50 knees, the femur only in 11 knees, the tibia only in 12 knees, and 57 had an isolated polyethylene revision. We found 5 patients with a mismatch between the patella and femoral components and 30 cases with patella component wear identified intraoperatively. RESULTS: At final follow-up, there were no reoperations on any patella and none were at risk of failure. There were 6 knees with a lateral patella tilt beyond 10°, but none were subluxed. Knee Society Scores averaged 85 ± 17.2 points at final follow-up. CONCLUSION: At midterm follow-up in this group of RTKA where the patella was not revised, we identified no subsequent failures of the patella. This is despite the presence of mild patella polyethylene wear and mismatched shapes in several knees. LEVEL OF EVIDENCE: III.

Incidence of Patella Baja Before and After Primary Total Knee Arthroplasty Based on Body Mass Index.

In the setting of total knee arthroplasty, patella baja has been associated with decreased range of motion and increased risk of certain extensor mechanism complications. The goal of this study was to determine whether obese patients had an increased prevalence of patella baja before and/or after primary total knee arthroplasty. A multicenter retrospective review of 5089 unilateral total knee arthroplasties performed between 1998 and 2012 for osteoarthritis was conducted. Only total knee arthroplasties with cemented modular, metal-backed constructs and patellar resurfacing were included. An a priori power analysis determined that 500 patients (stratified into 5 World Health Organization body mass index groups, matched by age and sex) were needed to detect a significant Insall-Salvati ratio difference of 0.07. Patella baja was defined as an Insall-Salvati ratio of less than 0.8. Preoperative and postoperative Insall-Salvati ratios were compared between groups and analyzed using linear regression and analysis of variance. Preoperatively, there was a higher prevalence of patella baja in the higher body mass index groups (>25 kg/m2) compared with normal weight patients (10% vs 6%; P=.02). Postoperatively, there was no difference in the prevalence of patella baja between the 2 groups (5% vs 5%; P=.91). On comparison of postoperative Insall-Salvati ratio with preoperative Insall-Salvati ratio, the higher body mass index groups had a greater change in Insall-Salvati ratio (Δ 0.10 vs Δ 0.07; P=.01). This is the first study to report an increased prevalence of patella baja in obese patients and to show that the prevalence normalizes to that of a control group after total knee arthroplasty. Obese patients undergoing primary total knee arthroplasty had a higher rate of preoperative patella baja. [Orthopedics. 2019; 42(2):90-94.].

Higher offset cross-linked polyethylene acetabular liners: is wear a significant clinical concern?

INTRODUCTION: Total hip arthroplasty (THA) is the 2nd most common total joint replacement surgery in the United States. However, not all THA devices perform well and need revised for several reasons including dislocation. Higher offset acetabular liners reduce this problem by creating a more anatomically/biomechanically natural hip joint, increasing soft-tissue tension, and accommodating larger femoral heads in smaller acetabular cups via increased polyethylene thickness. To our knowledge, however, in vivo wear (another failure mode) performance of offset acetabular liners remains unknown. METHODS: 2 cohorts of 40 individuals (0-mm, 4-mm offset acetabular liners, respectively) from a single surgeon's consecutive caseload were assessed. 6-week/5-year post-op radiographs were compared using a validated method using SolidWorks software to assess in vivo linear and volumetric wear rates. Resultant surgical offset was also quantified using this method. RESULTS: Linear wear rate for 0-mm and 4-mm offset cohorts were 0.01 ± 0.09 mm/year and 0.08 ± 0.12 mm/year, respectively. Volumetric wear rate for 0-mm and 4-mm offset cohorts were 30.4 ± 20.4 mm3/year and 61.6 ± 42.1 mm3/year, respectively. Both of these were statistically significant. Neither linear nor volumetric wear rate was correlated with resultant surgical offset. DISCUSSION: To our knowledge, this is the 1st study to compare in vivo wear performance of 0-mm and 4-mm offset acetabular liners. Although linear and volumetric wear rates were different between cohorts, neither reached previously established osteolysis thresholds. Moreover, wear rates were not correlated with resultant surgical offset. Finally, no patients in either cohort showed signs of osteolysis nor needed revision. As such, the clinical relevance of the wear rate differences is potentially less significant.

Right TKR Patients Treated with Enhanced Pain and Rehabilitation Protocols Can Drive at 2 Weeks.

An important milestone in the recovery following total knee replacement (TKR) is the ability to return to driving. With advances in pain control and the widespread introduction of rapid rehab programs, we hypothesized that the ability to drive would also return sooner than had been traditionally observed. In our group of consecutive right TKR patients, using a driving simulator, we showed that at the 2-week mark, 36 of the 40 patients tested had returned to their preoperative driving capabilities and the other 4 had reached baseline at 3 weeks. While the eventual decision to return to driving is complex and dependent on many factors, we conclude that one of the benefits of enhanced pain and rehab protocols is that patients undergoing right TKR can return to driving in most instances at the 2-week mark rather than the traditional 6-week mark.

Oral Multimodal Analgesia for Total Joint Arthroplasty.

BACKGROUND: Oral multimodal analgesia for hip and knee arthroplasty is increasingly used as part of enhanced recovery protocols designed to minimize early postoperative pain and to facilitate early discharge, while minimizing undesirable side effects related to single-agent opioid administration. METHODS: This article is a review of previously published data evaluating the use of various oral medications in the management of postoperative pain after lower extremity arthroplasty and was presented as part of a symposium at the November 2016 AAHKS Annual Meeting. RESULTS: Multimodal analgesia has been shown to reduce opioid consumption and side effects, with a positive effect on both early and longer term outcomes for hip and knee arthroplasty patients. Medications directed at multiple points on the pain cascade minimize pain by different mechanisms. Suggested dosing regimens are proposed. CONCLUSION: Oral multimodal analgesia incorporating a combination of opioid and nonopioid analgesics, selective and nonselective anti-inflammatory drugs, acetaminophen, and gabapentinoids are recommended as a part of a pre-emptive approach to pain management in patients undergoing hip or knee arthroplasty. Reduction of opioid consumption and minimization of side effects are primary outcomes, and prevention of chronic pain can positively affect long-term results.

The use of metaphyseal sleeves in revision total knee arthroplasty.

BACKGROUND: Bone loss in revision total knee arthroplasty is common. Various reconstruction options are available. The purpose of our study is to report on one such reconstruction option, titanium metaphyseal sleeves. METHODS: We describe a series of 45 patients (46 knees) who underwent revision total knee arthroplasty and were treated with a porous metaphyseal sleeve between August 2000 and September 2009 at two centers. Patients were followed for a minimum of four years, and at final follow-up, 40 patients (40 knees) were available for review. Patients were evaluated using The Knee Society's Knee Scoring System at each follow-up. Radiographs (standing anteroposterior, lateral, and sunrise views) were taken at six weeks, three months, and final evaluations. RESULTS: Mean Knee Society Scores increased from 36 (range 10 to 69) pre-operatively to 90 (range 38 to 100) at final follow-up. Mean alignment on final radiographic evaluation was 5° (range 3° to 8° valgus). Mean pre-operative alignment was 6° (range 15° varus to 18° valgus). Mean range of motion was 125° (range 80° to 140°) pre-operatively and 115° (range 95° to 130°) postoperatively. One device failed to achieve ingrowth and was revised at two years. All other knees were radiographically stable and ingrown. CONCLUSIONS: Metaphyseal sleeves provide an alternative for bone loss reconstruction in revision total knee arthroplasty. LEVEL OF EVIDENCE: III.

The "midsulcus line" as a landmark for tibial resection during total knee arthroplasty.

BACKGROUND: Proper tibial alignment is an important goal of total knee arthroplasty. Most surgeons agree that tibial coronal alignment should be within three degrees of neutral mechanical alignment. The "midsulcus line" is a line drawn along the sulcus of the tibial spines, and then the line is continued in the sagittal plane and extended onto the anterior tibia where it intersects the tibial tubercle approximately 3 to 4mm lateral to the tubercle's medial border. The tibial cut was then made perpendicular to this line. The aim of our study was to assess, using CT scans, whether this line provided a consistent guide for planning the tibial cut in total knee arthroplasty. METHODS: We reviewed the CT scans of the knees of 107 patients with osteoarthritis who had undergone a CT scan for planning of custom cutting guides. The midsulcus line was drawn on all scans. RESULTS: We found that in 105 of 107 knees, a perpendicular cut to this tibial landmark would have delivered a cut surface within three degrees of neutral mechanical alignment. CONCLUSIONS: The midsulcus line is a reliable landmark for planning the tibial resection in total knee arthroplasty. LEVEL OF EVIDENCE: III.

A state-of-the-art pain protocol for total knee replacement.

Total knee replacement is acknowledged as a successful and durable operation, but recovery from this surgery is often lengthy and painful. A great deal of attention has recently been directed at enhancing this recovery, most of which has focused on improvements in perioperative pain control. Various protocols have been suggested. This article discusses a pain management program that uses local infiltrative analgesia with a specific "cocktail" which, when combined with an oral multimodal pain regimen, has led to excellent patient satisfaction and a substantially shorter length of stay.

Is there an association between whole-body pain with osteoarthritis-related knee pain, pain catastrophizing, and mental health?

BACKGROUND: Greater levels of self-reported pain, pain catastrophizing, and depression have been shown to be associated with persistent pain and functional limitation after surgeries such as TKA. It would be useful for clinicians to be able to measure these factors efficiently. QUESTIONS/PURPOSES: We asked: (1) What is the association of whole-body pain with osteoarthritis (OA)-related knee pain, function, pain catastrophizing, and mental health? (2) What is the sensitivity and specificity for different cutoffs for body pain diagram region categories in relation to pain catastrophizing? METHODS: Patients (n = 267) with knee OA undergoing elective TKA at one academic center and two community orthopaedic centers were enrolled before surgery in a prospective cohort study. Questionnaires included the WOMAC Pain and Function Scales, Pain Catastrophizing Scale (PCS), Mental Health Inventory-5 (MHI-5), and a pain body diagram. The diagram documents pain in 19 anatomic areas. Based on the distribution of the anatomic areas, we established six different body regions. Our analyses excluded the index (surgically treated) knee. Linear regression was used to evaluate the association between the total number of nonindex painful sites on the whole-body pain diagram and measures of OA-related pain and function, mental health, and pain catastrophizing. Generalized linear regression was used to evaluate the association between the number of painful nonindex body regions (categorized as 0; 1-2; or 3-6) with our measures of interest. All models were adjusted for age, sex, and number of comorbid conditions. The cohort included 63% females and the mean age was 66 years (SD, 9 years). With removal of the index knee, the median pain diagram score was 2 (25(th), 75(th) percentiles, 1, 4) with a range of 0 to 15. The median number of painful body regions was 2 (25(th), 75(th) percentiles, 1, 3). RESULTS: After adjusting for age, sex, and number of comorbid conditions, we found modest associations between painful body region categories and mean scores for WOMAC physical function (r = 0.22, p < 0.001), WOMAC pain (r = 0.20, p = 0.001), MHI-5 (r = -0.31, p < 0.001), and PCS (r = 0.27, p < 0.001). A nonindex body pain region score greater than 0 had 100% (95% CI, 75%-100%) sensitivity for a pain catastrophizing score greater than 30 but a specificity of just 23% (95% CI, 18%-29%) . A score of 3 or greater had greater specificity (73%; 95% CI, 66%-79%) but lower sensitivity (53%; 95% CI, 27%-78%). CONCLUSIONS: We found modest associations between the number of painful sites on a whole-body pain diagram and the number of painful body regions and measures of OA-related pain, function, pain catastrophizing, and mental health. Patients with higher self-reported body pain region scores might benefit from further evaluation for depression and pain catastrophizing. LEVEL OF EVIDENCE: Level III, therapeutic study.

Consensus Statement on Indications and Contraindications for Medial Unicompartmental Knee Arthroplasty.

Previous work, now nearly 30 years dated, is frequently cited as the "gold standard" for the indications and contraindications for medial unicompartmental knee arthroplasty (UKA). The purpose of this article is to review current literature on the indications and contraindications to UKA and develop a consensus statement based on those data. Six surgeons with a combined experience of performing more than 8,000 partial knee arthroplasties were surveyed. Surgeons then participated in a discussion, emerging proposal, collaborative modification, and final consensus phase. The final consensus on primary indications and contraindications is presented. Notably, the authors provide consensus on previous contraindications, which are no longer considered to be contraindications. The authors provide an updated and concise review of the current indications and contraindications for medial UKA using scientifically based consensus-building methodology.

A systematic review of clinical outcomes and survivorship after total knee arthroplasty with a contemporary modular knee system.

A systematic review appraising the clinical performance and safety of the primary SIGMA modular knee system (DePuy-Synthes, Warsaw, Ind.) found 5 registry reports and 53 journal publications reporting survivorship or postoperative increase in Knee Society scores on 241632 primary SIGMA knee arthroplasties. Pooled data from national joint registries and clinical studies on primary SIGMA knee survivorship were comparable. Both were higher than for all other knees in 5 national joint registries up to 5 years. Compared with pooled data from 2 independent systematic reviews of primary non-SIGMA knees, the SIGMA system provided comparable postoperative changes in Knee Society knee score and a nonsignificant trend of higher postoperative changes in Knee Society function score. This finding suggests that this knee system provides excellent durable results.