Unicompartimental Knee Arthroplasty Research Articles

Unicompartimental Knee Arthroplasty In Patients With or Without Patellofemoral Arthritis: 2-Year Clinical Outcome

Objectives Evaluate patients submitted to unicompartimental knee arthroplasty (UKA) by two surgeons with partial knee replacement expertise and, analyze the outcomes comparing a group of patients with preoperative isolated medial compartment arthritis to another group of patients with associated patellofemoral arthritis. Methods We conducted a retrospective cohort study to compare the clinical results of all patients submitted to UKA by two senior surgeons, between 2009 and 2020. All patients were submitted to partial knee arthroplasty using fixed-bearing Zimmer Unicondylar Knee System (ZUK). During analysis, they were divided into two groups, without patellofemoral arthritis (Group 1) and with patellofemoral arthritis (Group 2). Data collected from patient’s records included demographic information, range of motion (ROM), patient-reported outcome measures (PROMs) and preoperative radiographs. Only patients with minimum 2-year follow-up were included. Results Preoperative ROM was 122.6º (±6.2º) and 122.2º (±9.2º), in Group 1 and in Group 2, respectively (p-value = 0.9). While postoperative ROM was 114.5º (±2.9º) in Group 1 and 112.5º (±3.6) in Group 2 and, there was no statistical significance (p-value = 0.4). There was also no statistical significance regarding PROMs (Table 3). In Group 1, Oxford Knee Score was 17.1 (±1.8) and 40.2 (±2.1), before and after surgery, respectively. In Group 2, Oxford Knee Score changed from 18.8 (±1.9) to 40.5 (±2.5). The KOOS went from 129.3 (±15.2) preoperatively to 61.4 (±18.3) after surgery, in Group 1, while Group 2 evolved from 137.2 (±14.8) to 57.3 (±11.9). No complications were identified during the period studied. Conclusion UKA is an acceptable treatment option for unicompartimental tibiofemoral arthritis of the knee in patients with associated PFOA. There was an improvement in ROM of the knee, Oxford Knee Score and KOOS, with no differences between patients with or without PFOA.

The Traditional Intramedullary Axis Underestimates the Medial Tibial Slope Compared to Transmalleolar Sagittal Axis in Image-based Robotic-Assisted Unicompartimental Knee Arthroplasty.

The medial unicompartmental knee arthroplasty (mUKA) has been recognized as an excellent treatment for medial knee osteoarthritis. The posterior tibial slope (PTS) is measured radiographically with the intramedullary axis (IMA) to the tibial baseplate on the sagittal plane radiograph. However, in most computer-navigated or robotic mUKAs, the PTS is set from a transmalleolar axis (TMA).The PTS difference was evaluatedbetween the sagittal TMA and the sagittal IMA of patients undergoing a CT-based primary robotic-assisted mUKA.We retrospectively reviewed the preoperative computed tomography (CT) scans taken according to the MAKO system protocol (Stryker) of 67 patients undergoing mUKAs. We measured the angular difference between the IMA and the TMA in the sagittal plane.Using the TMA to set the PTS the estimation of the slope of the medial tibial plateau would increase by an average of 1.9 ± 3.2 degreescompared to the IMA. Furthermore, in nineknees, PTS was decreased.Tibial components implanted with the help of a CT scan-based preoperative planning MAKO will show an average of 1.9 degrees more than those measured on sagittal radiographs potentially of concern for knee kinematics. A universal language is needed to standardize the slope calculation and the respective reference axis used.

MT2 Operating Room (OR) and Sterilization Efficiencies for Total (TKA), Revision (rTKA) and Unicompartimental Knee Arthroplasty (UKA) Using a Handheld Robotic Assisted (RA) Surgical System

MT2 Operating Room (OR) and Sterilization Efficiencies for Total (TKA), Revision (rTKA) and Unicompartimental Knee Arthroplasty (UKA) Using a Handheld Robotic Assisted (RA) Surgical System

Sleep Apnea is Not an Obstacle for Outpatient Hip and Knee Arthroplasty

BackgroundUp to 25% of patients requiring hip or knee arthroplasty have sleep apnea (SA), and these patients have historically been excluded from outpatient programs. The objectives of this study were to evaluate same-day discharge failure as well as 30-day complications, readmissions, and unexpected visits. MethodsA retrospective case-control study comparing patients who have and do not have SA matched for age, sex and arthroplasty type (total hip arthroplasty, total knee arthroplasty, unicompartimental knee arthroplasty) who underwent primary outpatient surgery between February 2019 and December 2022 in 2 academic hospitals was conducted. Cases with mild SA, moderate SA with a body mass index (BMI) <35, and SA of all severity treated by continuous positive airway pressure machines were eligible. There were 156 patients included (78 cases). Complications were assessed according to the Clavien-Dindo Classification and the Comprehensive Complication Index. Continuous variables were evaluated by Student's T or Mann-Whitney tests, while categorical data were analyzed by Chi-square or Fisher tests. Univariate analyses were performed to determine discharge failure risk factors. ResultsThere were 6 cases (7.7%) and 5 controls (6.4%) who failed to be discharged on surgery day (P = .754), with postoperative hypoxemia (6, [3.8%]) and apnea periods (3, [1.9%]) being the most common causes. Higher BMI (odds ratio = 1.19, P = .013) and general anesthesia (odds ratio = 11.97, P = .004) were found to be risk factors for discharge failure. No difference was observed on 30-day readmissions (P = .497), unexpected visits (P = 1.000), and complications on the Clavien-Dindo Classification (P > .269) and Comprehensive Complication Index (P > .334) scales. ConclusionsSelected patients who have SA can safely undergo outpatient hip or knee arthroplasty. Higher BMI and general anesthesia increased the odds of same-day discharge failure. Level of EvidenceLevel III, Case-control Study.

Unicompartmental knee arthroplasty (UKA) for primary spontaneous osteonecrosis of the knee (SONK): a systematic review.

The role of unicompartmental knee arthroplasty (UKA) in spontaneous osteonecrosis of the knee (SONK) is still controversial. We performed a systematic review to evaluate all available current literature on UKA in the setting of SONK. A comprehensive electronic research was performed using the PubMed, Embase, Web of Science, and Cochrane databases with keywords related to SONK and knee arthroplasty. Studies were selected with predetermined inclusion criteria: 1) studies that specifically assessed SONK treated with UKA; 2) studies reporting implant survival rate and global clinical outcomes; 3) studies with a minimum follow up of 1 year. We excluded articles not written in English, articles that did not differentiate between primary and secondary osteonecrosis and articles published before 2000. The overall research process produced 19 studies. We extrapolated data of a total of 717 unicompartimental knee arthroplasty procedures (1,39% lateral UKA, 98,61% medial UKA). Extracted data include years of follow-up, patient demographics, laterality of lesion, radiological findings, unicompartimental knee arthroplasty implants, reason of revision, revision rate, maximum knee flexion, knee clinical outcomes score, and Kaplan-Meier survival curves. The data collected show that UKA had acceptable survival rates as well as revision rates and good clinical outcomes both in the short- and long-term. UKA is an optimal treatment choice for primary SONK when correctly indicated in a carefully selected subset of patients, with no significant difference compared to osteoarthritis. Attention must be paid to distinguish the primary from secondary SONK, as the latter could lead to worse outcomes.

Robotic-assisted unicompartimental knee arthroplasty performed with Navio system: a systematic review.

Robotic-assisted arthroplasty is a relatively modern concept, quickly arising in its use. The aim of this systematic review is to assess, according to the existing literature, which are the functional and clinical outcomes and component positioning and implant survivorship of unicompartmental knee arthroplasty surgery performed using an image-free hand-held robotic system. Moreover, we analyzed whether there are significant differences and advantages compared to conventional surgery. A systematic review has been performed on studies published between 2004 and 2021, on the electronic library databases, according to the Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) statement. The inclusion criteria were all studies described as unicompartmental knee arthroplasty performed with the Navio robotic system. Fifteen studies were included, and 1,262 unicondylar knee arthroplasties were analyzed. These studies showed a satisfactory recovery of joint function, with a good range of motion (extension <5° and flexion which ranged from 105° to 130.3°) in patients of the NAVIO group. The revision rate was <2% while the infection rate <1%; no postoperative transfusion was needed in all UKA implanted. The use of a robotic tool for unicompartmental knee arthroplasty (UKA) could lead to a better implant positioning and joint alignment than conventional surgery. There is still limited evidence to support that the use of this robot in unicompartmental knee arthroplasty is a greater survivorship than other systems or conventional techniques; therefore, a long-term follow-up is needed.

Higher activity level after opening wedge high tibial osteotomy compared to medial unicompartimental knee arthroplasty in a selected cohort of advanced age: A propensity score-matched analysis

BackgroundHigh tibial osteotomy (HTO) and medial unicompartmental knee arthroplasty (mUKA) are accepted treatment for medial knee osteoarthritis (OA). Patients often present meeting indications for both procedures. The purpose of this study was to compare results after MOWHTO and UKA in a matched population of patients older than 50 years. MethodA retrospective analysis searching for patients older than 50 years meeting indication both for UKA and MOWHTO was performed. A propensity score matching (PSM) based on demographics and clinical data was performed. Tegner activity scale (TAS), Lysholm knee score (LKS) and numeric rating scale for pain (NRS) were recorded prospectively prior to surgery, at 6 months and after a minimum of 4 years. Results64 UKA and 71 MOWHTO were found. Mean follow up was similar (54,05 ± 4,80 and 52,62 ± 3,91). A significant improvement was found in both groups for all outcomes at 6 months and at final follow up. PSM yielded 29 pairs. Patients treated with MOWHTO showed superior TAS scores at 6 months (3,41 ± 0,50 vs 3,10 ± 0,56; p < 0,05) and at final follow up (3,83 ± 0,80 vs 3,27 ± 0,59; p < 0,005). NRS and LKS were comparable between groups. ConclusionsMOWHTO performed using an open wedge technique, with locking plate and a fast rehabilitation protocol guaranteed higher level of activity than UKA in patients older than 50 years. Difference is significant already at 6 months and last longer than 4 years.Level of evidence: III.

Is combined robotically assisted unicompartmental knee arthroplasty and anterior cruciate ligament reconstruction a good solution for the young arthritic knee?

Anterior cruciate ligament (ACL) deficiency can be a consequence or a cause of femoro-tibial osteoarthritis (OA). Several studies have published satisfactory outcomes of unicompartimental knee arthroplasty (UKA) and combined ACL reconstruction despite its absence classically being considered a contraindication. A major challenge in the ACL deficient knee is obtaining appropriate gap balancing and limb axis. Robotically assisted UKA allows for precise control of these factors; however, it's utilisation as a tool with combined ACL reconstruction and UKA has not been described. The purpose of this study was to evaluate the clinical and radiological outcomes of robotically assisted UKA with combined ACL reconstruction. This was a retrospective single-centre study of ten patients operated by a single surgeon from 2016 to 2020. All surgery was performed using a cemented fixed bearing UKA prosthesis (Journey uni, Smith and Nephew®) (8 medial, 2 lateral) inserted with the assistance of an image-free robotic-assisted system (BlueBelt, Navio, Smith and Nephew®). All ACL reconstructions were performed using hamstring autograft. Clinical assessment included International Knee Score (IKS) score, Tegner score and patient satisfaction. Radiological assessment was performed to assess radiolucent lines, progression of OA in the other compartments, Hip-Knee-Ankle angle and Posterior Tibial Slope. There were eight females (80%), mean age was 57 ± 7 [48-70], mean BMI was 26 ± 3 [22-31]. The mean follow-up was 45months ± 13months [24-66]. Mean post-operative IKS knee and function score were respectively 96 ± 4.5 [88-100] and 93 ± 8.2 [74-100], mean Tegner score was 4.5 ± 1.4 [3-6]. Nine patients (90%) returned to sport; one patient (10%) was dissatisfied because of residual pain preventing a return to a desired level of sport. 100% of the radiological objectives were achieved. No radiolucent lines were seen at the last follow-up. There were two re-operations (20%) for stiffness requiring arthroscopic arthrolysis at two and threemonths respectively following surgery, with full recovery of the flexion at the last follow-up in both cases. No other complications were observed. Robotic UKA associated with ACL reconstruction provides satisfactory early patient outcomes and accurate implant positioning. The first results in terms of return to sports were promising.

Fixed-bearing unicompartmental knee arthroplasty provides a lower failure rate than mobile-bearing unicompartimental knee arthroplasty when used after a failed high tibial osteotomy: a systematic review and meta-analysis.

Despite the fact that the choice of bearing design has been thought to influence the functional outcomes and longevity of unicompartimental knee arthroplasty (UKA), there is a lack of clinical evidence supporting the decision-making process in patients who have undergone high tibial osteotomy (HTO). A systematic review of studies was carried out that reported the outcomes of fixed-bearing (FB) or mobile-bearing (MB) medial UKA in patients with a previous HTO. A random effect meta-analysis using a generalized linear mixed-effects model to calculate revision rates was done. Seven retrospective cohort studies were included for this study. Regarding the fixation method, 40 were the FB-UKA and 47 were MB-UKA. For both groups, the mean post-operative follow-up was 5.8years. The survival rates were 92% for the FB-UKA with a mean follow-up of 10years. For the MB-UKA, it ranged from 35.7 to 93%, with a mean follow-up of 4.2years. For the FB, the time to revision was reported as 9.3years, while 1.2, 2.5 and 2.91years was reported for the MB. The results of the meta-analysis showed that the revision rate for the patients receiving a FB-UKA after failed HTO was 8%, compared to 17% in those who received an MB-UKA. The results of the review suggest that the use of the FB-UKA is associated with lower revision rates and a longer survival time than the MB-UKA and have similar functional ability scores.Level of evidence: III (systematic review of level-III studies).

Return to Sport Activity in the Elderly Patients after Unicompartmental Knee Arthroplasty: A Systematic Review and Meta-Analysis.

In patients with knee osteoarthritis, when only medial or lateral compartment of the knee is involved, unicompartimental knee arthroplasty (UKA) is a reliable option for addressing the symptoms and restore function. The main aim of the present review is to systematically collect the available evidence concerning the return to sport activity in the elderly patients after UKA. An electronic search was carried out on the following databases; Pubmed-Medline, Cochrane central, and Scopus, searching for randomized controlled trials, prospective cohort studies, retrospective case-control studies, and case series. Data concerning the evaluation of the return to sport (RTS) and of functional outcomes in the elderly patients after UKA surgery. MINORS score was used to assess the risk of methodological biases. Odds ratios and raw proportions were used to report the pooled effect of UKA on the return to sport in comparative and non-comparative studies, respectively. Same level RTS in elderly patients was of 86% (pooled return proportion 0.86, 95%CI 0.78, 0.94), showing also better relative RTS and time to RTS of patients undergoing UKA, in comparison to those undergoing TKA. Sport-specific RTS showed that higher return rates were observed for low-impact sports, whereas high-impact sports prevented a full return to activities. UKA is a valid and reliable option for elderly patients to satisfactorily resume their sport practice, especially for low impact activities. The rate of return to sports following UKA is higher than TKA.

Is robotic-assisted unicompartmental knee arthroplasty a safe procedure? A case control study.

The hypotheses were that firstly there is few early specific complications due to the use of a robotic-assisted system for unicompartimental knee arthroplasty (UKA), and secondly there are less revisions and complications after robotic-assisted UKA than after conventional UKA. 200 robotic-assisted UKA (175 patients) and 191 conventional UKA (179 patients) were performed between 2013 and 2018 from the same center. Revisions, intraoperative and postoperative complications, functional and radiological results were collected at the most recent follow-up. At the most recent follow-up (≥ 1year), revision rates were 4% (n = 8/200) for robotic-assisted UKA and 11% (n = 21/191) for conventional UKA (p = 0.014). Reoperation rates without implant removal were comparable in the robotic and conventional group (7.3% vs 8.6%). Complication rates for stiffness (4.7% vs 4.2%) and infection (1% vs 1.6%) were comparable in both groups. There was no specific complication related to the robotic-assisted system (no soft tissue or bone lesion caused by the use of the robotic-assistance and no complication related to the use of navigation pins). The KSS function scores were higher following robotic-assisted UKA (p = 0.01). Satisfaction rates and contralateral OA were comparable in the two groups. No complications due to the robotic-assisted system were found in this study. There was no difference in the general complications rate between both groups. Robotic-assisted UKA has a lower revision rate compared to conventional technique UKA at the short-term follow-up. III. This is the first paper comparing revision rate and clinical outcome between UKA performed using the NAVIO robotic system and a conventional technique and searching for specific complication related to the use of the NAVIO robotic system.

Retrospective Revision of Knee Arthroplasty Performed using Robotically Assisted Technique

Minimally invasive unicompartimental knee arthroplast is characterized by numerous advantages, in comparison with total knee arthroplasty, such as earlier recovery, less post-operative morbidity, improved knee function. These advantages have been obtained also thanks to the robotic assisted surgery, that allow to plan the arthroplasty more accurately, with improved outcome for patient. A device for robotically assisted arthroplasty that has emerging as the best device for unicompartimental knee arthroplasty. It works on compute tomography acquisitions and predicts the correct position for prosthesis, the ligament stress and the final extension and flection of the treated leg. In this study, we describe the results obtained on 876 patients subjected to different procedures in which the robotic device for knee arthroplasty has been employed to perform 919 knee implants. Statistic evaluation of different parameters, measured before and immediately after prosthesis placement, demonstrate the accuracy of robotic device for knee arthroplasty, in facilitate and assist surgeon procedures in order to obtain the best results for patients. By robotically assisted arthroplasty a negative outcome can be prevented because the positioning of the prosthesis is more correct and programed already before surgery, aligning rightly tibia and femur, balancing correctly the ligament and optimizing bone preparation.

Management of medial compartment knee arthritis with unicompartimental arthroplasty: our experience

Objectives:the purpose of this presentation is to review the indications and benefits for the use of the Unicompartimental Knee Arthroplasty (UKA) for the treatment of the anteromedial osteoarthritis of the knee, and to make an early report of our series.Methods:37 UKA were performed by our group between 2013 y 2016, as a first experience, with 22 male patients and 15 females. The limit ages were 28 and 85 years. All received a Vangard PFR System (Zimmer Biomet Warsaw In).Results:All the patients reported a better life quality, and the main difference that we noticed is the subjective feeling that the operated knee felt “like own” by the patients, which is consistent with the fact that the ligaments were intact, even in the 6 cases where we performed an ACL reconstruction, (although we know that the stable knee is a known prerequisite for this kind of surgery).Conclusion:The unicondilar knee replacement is a technically demanding procedure that requires a careful patient selection and a steep learning curve, but even in this short series, we agree with most of the recent papers that state the benefits of the UKA, and we are looking to start a prospective series of cases to evaluate the outcomes with functional scores.

Effect of age on cost-effectiveness of unicompartimental knee arthroplasty compared with total knee arthroplasty in the US.

Originally conceived as a treatment for joint disease in the elderly, joint replacement surgery grew substantially during 1990s and 2000s in both the elderly and the younger patient population, with an increasing utilization expected to exceed one million annually by 2020 (1).

Tecnica di impianto e primi risultati con l’utilizzo del robot nella protesi monocompartimentale

Retrospective analysis led on the first 100 medial or lateral Unicompartimental Knee Arthroplasty cases with Robotic assisted technique (MAKOplasty) and Restoris MCK implants. Clinical outcomes grow out of this pre and post-operative study with a follow-up of 1–3–6 months.

Cemented all polyethylene tibial insert unicompartimental knee arthroplasty: A long term follow-up study

Unicompartimental knee arthroplasty outcome is sometimes compared to total knee arthroplasty but various implant parameters might greatly influence this outcome. The objectives of this study were to report the results of a consecutive series of 172 all-polyethylene unicompartmental knee arthroplasties (UKAs) and to detail possible factors of success and failure. It is possible to outline implant and technique factors determining success or failure in unicompartimental knee arthroplasty. One hundred seventy-two HLS-type cemented resurfacing UKAs, with the femoral implant made of chrome-cobalt and the tibial implant tibial entirely in polyethylene (without anchorage studs) were consecutively implanted between 1988 and 2004 in 134 patients (111 females and 23 males) in our center according to the indications established in 1988, using the same technique for each surgery. The patients' mean age was 72.2 years (range, 25-90 years). The review rate was 83.7% (144 UKAs), with a mean follow-up of 62.3 months (range, 24-160 months). The series included 84 medial UKAs and 60 lateral UKAs. The clinical data were analyzed using the IKS criteria and the patients had a complete radiological evaluation before surgery and at the last follow-up. The rate of satisfied or very satisfied patients was 97.2%. No pain or slight pain was found in 81% of the cases. The mean flexion was 133 degrees (range, 85-150 degrees). The mean knee score varied from 63.6 before surgery to 91.5 (90.4 for medial UKAs and 92.9 for lateral UKAs) and the function score from 63.6 to 83.8 (84.7 for medial UKAs and 82.6 for lateral UKAs). The mean range of motion was 133 degrees (range, 85-150 degrees), better than the medial UKAs for osteonecrosis. The mean residual deformity was 4 degrees varus for the medial UKAs and 2 degrees valgus for the lateral UKAs. A radiolucency was found in 23% of the cases (20% tibial and 3% femoral), nonprogressive in all cases. In 87.2% of the cases, the opposite femorotibial compartment remained radiologically normal. No progression to osteoarthritis in the femoropatellar joint required additional surgery. Sixteen patients required revision surgery: in six cases, the implant was removed and a total prosthesis implanted (one late infection, one case of involvement of the opposite compartment, and four cases of tibial component loosening). In the other cases, one tibial baseplate was changed, five arthroscopies were done, and four unicompartmental knee replacements were done on the opposite compartment. The Kaplan-Meier survival rate (taking into account the revisions with implant change) was 95.6. The results of this series were very satisfactory and were similar to recent series in the world literature that showed survival rates between 90 and 98% at 10 years, rates that are equivalent to those found for total knee replacements. The mean flexion range of motion found was higher than the majority of other recent series, probably because of the precise patient selection in the present study, a minimally invasive approach, and the femoral implant design with an ascending condylar posterior cut. The deterioration of the contralateral compartment is frequently reported, but was perhaps prevented by the absence of overcorrection and patient selection. In this series, none of the UKAs was revised for wear. We explain this by the systematic preservation of a moderate undercorrection, particularly for medial UKAs, the quality of the polyethylene, and a selection based on patient weight and age. The option of an all-polyethylene tibial implant, with minimal bone cuts (femoral resurfacing), makes excellent long-term results possible.

The femoropatellar endoprosthesis--still of value today?

Aim of this study was the examination of clinical middle- and long-term results of total femoropatellar endoprostheses type Lubinus (Link, Germany). From 1983 to 1996 12 patients (15 joints) underwent total femoropatellar joint replacement (type Lubinus, Link, Hamburg). All of them have been controlled 7.2 +/- 2.6 years (2 to 12 years) after surgery. The indication was primary osteoarthritis in 6, chondrocalcinosis in 2 and rheumatoid arthritis in 7 cases. In addition to the femoropatellar implants femorotibial endoprostheses have been used in 10 knees: 2 unicondylar medial, 1 unicondylar lateral and 7 bicondylar unicompartimental ones. According to a modified Hungerford knee rating scale 8 knees resulted excellent, 2 fair and 4 poor. One knee was excluded after revision surgery due to a loosened tibial component of a medial unicompartimental knee arthroplasty. The 4 poor outcomes resulted from femoropatellar replacements in chondrocalcinosis (2 cases), rheumatoid arthritis and osteoarthritis, (one case each), affecting the femorotibial joint as well. In those cases of simultaneous femorotibial joint affection--even if this is merely slight and beginning and if the femoropatellar complaints are actually clearly dominating--the sole femoropatellar surface replacement seems to be contraindicated according to our experiences. Providing correct and strict indications this endoprosthesis can be recommended for sole femoropatellar osteoarthritis especially since loosening of endoprosthetic components was not been found in this study.

Lateral unicompartimental knee arthroplasty: indications, technique and short-medium term results

Lateral unicompartmental knee arthroplasty (UKA) is a valid alternative treatment in the event of arthritis confined to the lateral compartment. This paper examines its indications, technique and short to medium-term results. A total of 159 Miller-Galante cemented UKA prostheses (Zimmer, Warsaw, Indiana) were implanted consecutively (131 medial and 28 lateral) by the same surgeon. This study investigates 28 lateral UKAs in 27 patients. Twenty-five implants in 24 patients (including a subject operated bilaterally) were followed up for 12-60 months. Three patients were discarded on account of to short a follow-up period. The Hospital for Special Surgery (HSS) knee score was used to compare the pre- and post-operative results of the lateral UKA patients. The HSS score improved from a pre-op mean of 59.92 (range 48-68) to 88.04 (range 71-95) at the last follow-up. There was a positive increase in the pain, function and ROM components of the score. The lateral UKA prosthesis can be regarded as a sound alternative to total knee replacement. Correct patient selection on the basis of optimum surgical indications, however, is essential.

Salvage of infected unicompartimental knee arthroplasty

Two-stage arthroplastyresection was carried out on three patients with a serious infection of a single compartment knee prosthesis. In two patients, a block of antibioticcement was inserted, simulating the form of the condyle and the plateau; and in the third, the prosthesis was extracted with no further insertion. All three patients underwent antibiotherapy and when they showed clear signs of being cured (an average of 5 months), a total prosthesis was implanted. One year after revision, no residual infection was found. The results, using the Hospital for Special Surgery scale, are wery good in two of the cases and fair in the other (patient without cement).