Minimum 15-Year Survival of a Biconvex Inlay Patellar Component in Primary Total Knee Arthroplasty: An Analysis of 2,530 Total Knee Arthroplasties From a Single Institution.

BACKGROUND: Routine patellar resurfacing during primary total knee arthroplasty (TKA) remains controversial. To our knowledge, there are no studies reporting the long-term performance of a cemented biconvex all-polyethylene inlay component implanted at the time of primary TKA. The purpose of this study was to examine the 15-year survivorship and long-term clinical outcomes of this biconvex inlay patella used at our institution. METHODS: We retrospectively reviewed our prospectively collected institutional database and identified 2,530 patients who underwent cemented TKA with a single prosthetic design (from 1996 to 2007) where the patella was resurfaced using this cemented biconvex inlay patella. The mean age at surgery was 68 years (range, 29 to 93). The mean body mass index was 33.0 (range, 16.4 to 76.3), with 61.9% women. At the time of analysis, the mean time from surgery was 20.4 years (range, 15 to 26). We used Kaplan-Meier analysis to calculate survivorship at 15 years. We analyzed clinical outcomes using 3 patient-reported outcome measures collected prospectively. RESULTS: The 15-year survivorship with revision surgery for all causes as the end point was 97.1% (95% confidence interval 96.1 to 98.1%). The 15-year survivorship with revision surgery for a patella-related complication as the end point was 99.7% (95% confidence interval 99.4 to 1.0). At the final follow-up, patients showed significant improvement in scores for the Knee Society Clinical Rating System (P < .001), Western Ontario and McMaster University Osteoarthritis Index (P < .001), and Veterans Rand 12-Item Health Survey physical component (P < .001). CONCLUSIONS: Routine patellar resurfacing using a biconvex inlay patellar component has excellent survivorship and a low rate of complications at 15 years post-TKA.

Cementless Total Knee Arthroplasty: Does Age Affect Survivorship and Outcomes?

BACKGROUND: Despite the growing popularity of cementless total knee arthroplasty (TKA) in younger patients, the outcomes are unclear in the elderly population. We aimed to compare the clinical outcomes and survivorship of cementless TKA between different age groups. METHODS: Utilizing our prospectively collected institutional database, we retrospectively reviewed all patients undergoing primary cementless TKAs at a tertiary care institute. We identified 347 TKA, which were divided into 3 groups based on age at the time of surgery. Group A was ≤ 60 years, Group B was 60 to ≤ 70 years, and Group C was > 70 years. We compared clinical outcomes (Knee Society Clinical Rating System [KSCRS], Western Ontario and McMaster University Osteoarthritis Index [WOMAC], and Veterans Rand 12 Item Health Survey [VR-12]) and survivorship between the groups. RESULTS: At final follow-up, range of motion, KSCRS, WOMAC, and VR-12 physical score were comparable (P > .05). The VR-12 Mental score was higher in Group B and Group C than in Group A (P = .003). Compared to preoperative scores, the change in KSCRS, WOMAC, and VR-12 physical and mental scores was comparable at the final follow-up (P > .05). No patient underwent revision for aseptic loosening. CONCLUSIONS: There were no cases of revision surgery for aseptic loosening in our cohort of 347 cementless TKAs. Patients > 70 years of age undergoing cementless TKA can achieve clinical scores equivalent to those of younger patients at short term (2-year) follow-up. Longer-term survivorship is still required, but based on early data, cementless TKA can be a safe option for older patients.

Secondary Patellar Resurfacing Following Primary Unresurfaced Total Knee Arthroplasty: Beware of the Incidence of Late Patellar Erosion.

BACKGROUND: The primary aim of this study was to evaluate secondary patellar resurfacing (SPR) indications and rates in a single-surgeon series utilizing a modern TKA design and additionally, to review the functional outcomes of patients after undergoing SPR. METHODS: A retrospective review of a prospectively collected institutional database was performed. All patients undergoing primary TKA by a single surgeon between 2013 and 2021 were included. During this time, the senior surgeon resurfaced the patella selectively. Patients were divided into the primary resurfaced (PR) and the primary unresurfaced (UR). All patients undergoing SPR in the UR group were identified, their radiographs reviewed, and their clinical outcomes assessed. During the study period, 1,511 TKAs were performed, with 73.1% (1,105 TKAs) being unresurfaced. RESULTS: The all-cause revision rate was 1.2% in the PR group and 3.6% in the UR group. The rate of SPR in the UR group was 2.0% (22 of 1,105 TKAs). No patient in the PR group underwent revision surgery for a patellar complication. The mean age at primary TKA for those undergoing SPR was 65 years (range, 50 to 78). The average time for SPR from primary TKA was 3.4 years (range, 1.1 to 8.8). Postoperative radiographic progression of patellar erosion, in combination with new onset anterior knee pain, was the indication for SPR in 14 of the 22 (63.7%) SPR cases. After SPR, the Western Ontario and McMaster University Osteoarthritis Index score (P < .001) and Knee Society Score (P < .001) improved from pre-SPR. CONCLUSIONS: Secondary patellar resurfacing (SPR) was the most common (55%) reason for revision surgery after primary UR TKA in this series. An SPR improved clinical outcomes in symptomatic patients. Surgeons should consider patellar resurfacing for all patients undergoing primary TKA to reduce the burden of revision surgery post-TKA. Additionally, the paradigm that late SPR does not improve clinical outcomes needs to be revisited.

Addition of Surgeon-Administered Adductor Canal Infiltration to the Periarticular Infiltration in Total Knee Arthroplasty: Effect on Pain and Early Outcomes.

BACKGROUND: Our aim was to study the additive effect of surgeon-administered adductor canal infiltration (SACI) over routine periarticular infiltration (PAI) on pain control [morphine consumption and pain score by the visual analog scale (VAS)] and early function [flexion and Timed Up and Go (TUG) test] post-total knee arthroplasty (TKA). METHODS: We prospectively randomized 60 patients into 2 groups. Group I patients received the standard PAI, whereas in Group II, the patients received a SACI in addition to the PAI. The total volume of the injected drug and the postoperative pain management protocol were the same for all. The number of doses of patient-controlled analgesia (PCA) used for breakthrough pain was recorded as PCA consumption. For early function, flexion and the TUG test were used. The VAS score and PCA consumption were compared between the 2 groups by using analyses of variance with post hoc tests as indicated. The TUG test and flexion were compared using Student t tests. The level of significance was set at 0.05. RESULTS: The PCA consumption in the first 6 hours was significantly higher in Group I (P = .04). The VAS at 6 hours was significantly lower in Group II (P = .042). The TUG test was comparable between the 2 groups preoperatively (P = .72) at 24 hours (P = .60) and 48 hours (P = .60) post-TKA. The flexion was comparable between the 2 groups preoperatively (P = .85) at 24 hours (P = .48) and 48 hours (P = .79) post-TKA. CONCLUSIONS: Adding a SACI to PAI provides improved pain relief and reduces opioid consumption without affecting early function post-TKA. A SACI avoids the need for an anesthesiologist or specialized equipment with no added operating time and minimal added cost. We recommend routine use of SACI for all patients undergoing TKA.

Posterolateral Corner of the Knee: An Update on Current Evaluation and Management Strategies.

Historically, the posterolateral corner (PLC) of the knee has been labelled as the "dark side" of the knee. The PLC is not a single structure but a confluence of multiple structures, including the lateral collateral ligament, popliteus muscle-tendon unit, and popliteofibular ligament. Understanding the individual components and their function is important to successfully identify these injuries. PLC injuries are commonly associated with cruciate injuries, and its early recognition is important to achieve successful outcomes. Injury to the PLC should be treated on a case-by-case basis, and an appropriate algorithm is required to manage them. Multiple surgical techniques ranging from primary repair to anatomic reconstruction have been reported in managing these injuries. We present the latest literature on the anatomy, biomechanics, clinical presentation, imaging, available techniques, and current management recommendations. There is a special focus on the pathoanatomy, which will help guide the treatment of these injuries.

Short Term Outcomes (Average Follow-Up of 2.4 Years) of a Constrained Acetabular Liner in Primary and Revision Total Hip Arthroplasty.

BACKGROUND: As instability continues to be a burden post-total hip arthroplasty (THA), there has been a controversial discussion on the ideal implant choice. We report the outcomes of a modern constrained acetabular liner (CAL) system in primary and revision THA at an average follow-up of 2.4 years. METHODS: We performed a retrospective study of all patients undergoing primary and revision hip arthroplasty and being implanted with the modern CAL system from 2013 to 2021. We identified 31 hips, of which 13 underwent primary THA and the remaining 18 underwent revision THA for instability. RESULTS: Of those implanted with CAL primarily, 3 had concomitant abductor tear repair and gluteus maximus transfer, 5 had Parkinson's disease, 2 had inclusion body myositis, 1 had amyotrophic lateral sclerosis, and the remaining two were over 94 years of age. All patients implanted with the CAL had active instability post-primary THA and underwent only liner and head exchange without revision of the acetabular or femoral components. At an average follow-up of 2.4 years (ranging from 9 months to 5 years and 4 months), we had 1 case (3.2%) of dislocation post-CAL implantation. None of the patients undergoing surgery with CAL for active instability had a redislocation. CONCLUSION: In conclusion, a CAL provides excellent stability in both primary THA in high-risk individuals and revision THA in cases of active instability. There were no dislocations when using a CAL to treat active instability post-THA.

Decreased Femoral Trochlear Length Associated With Increased Anterior Knee Pain Following Total Knee Arthroplasty: A New Anatomical Perspective.

BACKGROUND: Anterior knee pain (AKP) and patello-femoral crepitus (PFCr) continue to plague total knee arthroplasty patients despite advances and modifications to implant design and surgical techniques. We present our study of the femoral trochlear length measurement preimplantation and postimplantation and its association with AKP/PFCr and clinical scores. METHODS: Using computer navigation, we obtained several measurements in 263 total knee arthroplasty (posterior-stabilized) patients, which included femoral native trochlear measurement (NTM) and difference in trochlear length between implant and native trochlea. We report their association with Knee Society Score, Western Ontario McMaster University Arthritic Index, and AKP/PFCr at 1 year postoperatively. RESULTS: Mean Knee Society Score and Western Ontario McMaster University Arthritic Index scores were significantly worse in patients who had AKP (P = .005 and P = .002 respectively). Receiver operating characteristic curve showed a statistically significant association between NTM and AKP (Area under the curve = 0.609, P = .014). Lower the NTM, greater was the incidence of AKP. Analysis of the receiver operating characteristic curve identified the cutoff value of NTM to be ≤25.5 with sensitivity of 76.7(95% confidence interval - 57.7 - 90.1) and specificity of 46.9 (95% confidence interval - 41.9 - 55.1). Patients who had NTM of ≤25.5 had an odds ratio of 3.09 to have AKP. The difference in trochlear length ranged from 7.4 to 32.1 millimeters, indicating that postimplantation there was lengthwise overstuffing along the trochlea in every patient. CONCLUSION: We found that the shorter the native femoral trochlea and greater the difference between implanted and native trochlea, the higher was the occurrence of AKP. A mismatch in trochlear measurement preimplantation and postimplantation resulted in lengthwise overstuffing in the anterior knee causing AKP and PFCr.

Does Postoperative Intravenous Ferric Carboxymaltose Hasten the Recovery of Hemoglobin in Patients Post Total Knee Arthroplasty?

BACKGROUND: Timely and effective iron supplementation may help reduce the incidence of postoperative anemia and its associated problems. In this study, we aim to assess the efficacy of intravenous ferric carboxy maltose (FCM) on improving hemoglobin(Hb) level posttotal knee arthroplasty (TKA). METHODS: We retrospectively reviewed 263 patients who had undergone unilateral TKA with 157 patients in the study group (year 2019) and 106 in the control group (year 2016). Patients in the study group received FCM (500 mg IV) on postoperative day 1, whereas patients in the control group did not receive FCM or any other iron supplementation postoperatively. Hb levels were recorded preoperatively (Pr-Hb), postoperatively on day 3 (Day3-Hb) and postoperatively at 5(+1) weeks (Week5-Hb). Statistical analysis was performed using student's paired and unpaired t-tests. RESULTS: Pr-Hb and Day3-Hb levels were comparable in the control and study group, while Week5-Hb levels were significantly higher (P < .001) in the study group. The drop in Hb at Day3 from preoperative values was comparable between the two groups (P = 1.0). The rise in Hb from Day3 to 5 weeks was significantly higher in the study group as compared to the control group (P < .001). The difference between Pr-Hb and Week5-Hb was significantly lower (P < .001) in the study group compared to the control group. However, Week5-Hb in both groups remained lower than Pr-Hb (P < .001) in all patients. CONCLUSION: Intravenous FCM (500 mg) was found to be a safe method of iron supplementation to improve hemoglobin levels rapidly and consistently, post-TKA. We need to further study the additive effect of higher dose FCM (1000 mg) on hemoglobin recovery.

Ten- to 14-Year Results of a High-Flex Rotating Platform Knee Implant: A Follow-Up Report of a Prospective Cohort.

BACKGROUND: High-flex posterior stabilised rotating platform (PSRP) implant was introduced to provide for deep knee flexion. Few short-term results have been reported, but there are no long-term outcomes reported. METHODS: We prospectively followed 48 patients (53 knees) implanted with one such design. Inclusion criteria for implantation were patients with good pre-operative flexion and wishing to perform activities requiring deep knee flexion post-operatively, with femorotibial varus angle < 15° and having good flexion stability at trialling stage. Previously, we reported their outcomes at 2-6 years (FU-1). We now report their functional and radiological results at a minimum follow-up of 10 years (FU-2) in 39 patients (43 knees); 5 patients having died and 4 lost to follow-up. RESULTS: The mean pre-operative flexion of 124° improved to 130° at FU-1 and to 134° at FU-2. Flexion of 130° or more was seen in 59.6% knees at FU-1 and 74.42% knees at FU-2. At FU-2 mean Knee score was 90.5 and Function score was 67.8. Incidence of patellofemoral symptoms increased from 7.7% at FU-1 to 11.36% at FU-2. There were no cases of bearing spin out, osteolysis or revision surgeries. CONCLUSION: At a minimum 10-year follow-up, high-flexion PSRP design in selected patients yielded 100% survival. We recorded good knee flexion and knee society scores, with no case of spin out, implant loosening, osteolysis or revision surgery. Although deep knee flexion improved at longer follow-up, its use in ADL had reduced due to other age-related factors. There was increased incidence of patellofemoral symptoms.

Vitamin D Trajectory after Total Knee Arthroplasty: A Method for Quick Correction in Deficient Patients.

BACKGROUD: It has been widely reported that vitamin D (vit D) affects preoperative, postoperative, and long-term outcomes after total knee arthroplasty (TKA). Our aim was to study vit D trajectory after TKA and compare effects of oral versus intramuscular (IM) supplementation in insufficient patients and assess its effects on immediate functional recovery in the first 2 weeks after TKA. METHODS: Vit D levels < 30 ng/mL are considered insufficient. We prospectively enrolled 60 patients (20 per group): group I, vit D sufficient patients; group II, vit D insufficient patients given IM supplementation (cholecalciferol 6,00,000 IU); and group III, vit D insufficient patients given oral supplementation (cholecalciferol 600,000 IU). Vit D levels, knee flexion, Timed Up and Go (TUG) test results, and visual analog scale (VAS) score were recorded preoperatively and postoperatively on day 3 and 14. RESULTS: In group I, mean preoperative vit D significantly dropped at postoperative day (POD) 3 and POD 14 (p = 0.001). In group II, mean preoperative vit D rose at POD 3 and rose significantly at POD 14 (p = 0.001). In group III, mean preoperative vit D increased significantly at both POD 3 and POD 14 (p < 0.001). Also, in group III, the rise in vit D was significantly higher than that in group II both at POD 3 and POD 14 (p < 0.05). In group III, 19 of 20 insufficient patients became sufficient on POD 3 and all 20 by POD 14. In group II, even by POD 14, only 11 of 20 insufficient patients became sufficient. Functional parameters (flexion, change in flexion, TUG test results, and VAS score) were comparable (p > 0.05) in all groups. Changes in TUG test showed a significant increase in group II (48.5 seconds) when compared to group I (35.5 seconds) at POD 3 (p < 0.05), suggesting a slower recovery. It remained comparable (p > 0.05) between group III and group I. CONCLUSIONS: We found that vit D insufficient patients can be rapidly supplemented on the morning of surgery with a large dose of oral cholecalciferol 600,000 IU, and the effect was consistent over 2 weeks after surgery. Orally supplemented vit D insufficient patients also showed functional recovery comparable to vit D sufficient patients. IM supplementation increased vit D levels only at 2 weeks and the rise was significantly lower than oral supplementation. Interestingly, approximately 25% of vit D sufficient patients who were not supplemented after TKA became insufficient in the first 2 weeks postoperatively.

Rare Fungal Infection in Arthritic Knee After Stem Cell Injection Managed by Novel Staged Primary Arthroplasty: A Case Report.

CASE: A 72-year-old man with bilateral knee osteoarthritis treated elsewhere with bilateral intraarticular stem cell injections (SCIs) presented to us 2 months later with signs of infection in his left knee. Aspiration culture grew fungus Penicillium sp. First-stage total knee arthroplasty (TKA) included thorough joint debridement, lavage, standard bone cuts, and insertion of antibiotic-impregnated cement spacer. Second stage included spacer removal and final implantation. At the 1.5-year follow-up, he has a satisfactory clinical outcome without evidence of infection. CONCLUSION: As far as we know, this is the first reported case of infective fungal arthritis secondary to intraarticular SCI successfully managed by a staged primary TKA.

A 72-year-old man with bilateral knee osteoarthritis treated elsewhere with bilateral intraarticular stem cell injections (SCIs) presented to us 2 months later with signs of infection in his left knee. Aspiration culture grew fungus Penicillium sp. First-stage total knee arthroplasty (TKA) included thorough joint debridement, lavage, standard bone cuts, and insertion of antibiotic-impregnated cement spacer. Second stage included spacer removal and final implantation. At the 1.5-year follow-up, he has a satisfactory clinical outcome without evidence of infection. As far as we know, this is the first reported case of infective fungal arthritis secondary to intraarticular SCI successfully managed by a staged primary TKA.

A Simple, Stepwise, Outside-in Technique for Lateral Retinacular Release for Management of Patellar Maltracking During Total Knee Arthroplasty.

Lateral retinacular release is done to correct patellar maltracking in total knee arthroplasty. The inside-out technique is widely used but has associated risks. Our video describes a simple outside-in technique, done stepwise, and titrated according to the grade of maltracking that maximizes preservation of the superior lateral geniculate artery and preserves the synovium, avoiding complications such as hematoma formation, skin tenting, and wound discolouration. The technique is also effective in all severities of maltracking and with all types of implants.

What Is the Normal Trajectory of Interleukin-6 and C-reactive Protein in the Hours and Days Immediately After TKA?

BACKGROUND: Some patients with early periprosthetic joint infection (PJI) can be treated successfully using open débridement with polyethylene exchange rather than two-stage revision; however, the challenge is to diagnose PJI early. In late infection, C-reactive protein (CRP) and interleukin-6 (IL-6) are elevated, but shortly after surgery, CRP is difficult to interpret because it may be elevated even in the absence of infection, and we know little about the normal trajectory of IL-6 immediately after arthroplasty. If a deviation of biomarkers from their normal trajectory is seen, it may help guide the clinician toward early knee aspiration. QUESTIONS/PURPOSES: We studied the normal trajectories of IL-6 and CRP in the immediate hours and days after uncomplicated TKA and examined whether one or the other normalizes more quickly. METHODS: We studied serum IL-6 and CRP levels in 50 patients undergoing primary TKA at five time points: 12 hours preoperatively and postoperatively at 12 hours, 48 hours, 4 days, and 2 weeks. One surgeon operated on all patients using the same approach and postoperative management. The same laboratory methods were used each time. Results are presented as median and range. Repeated-measures analysis was done using Friedman's (nonparametric) test. No patient showed any clinical sign of infection during our study period. All patients were followed up until 1 year with no evidence of infection and good knee scores. RESULTS: IL-6 showed a sharp rise from its baseline with a preoperative median value of 6 pg/mL (range, 3-17 pg/mL) to a peak of median value of 133 pg/mL (range, 15-359 pg/mL) at 12 hours postoperatively. At 48 hours, IL-6 had declined to a median value of 82 pg/mL (range, 12-309 pg/mL). At 4 days, it had further declined to a median value of 22 pg/mL (range, 5-67 pg/mL). At 2 weeks, IL-6 reached a median value of 7 pg/mL (range, 3-14 pg/mL), which was not different from the baseline median value with the numbers available (p = 0.455). CRP showed a gradual rise from its baseline preoperative median value of 2 mg/L (range, 1-17 mg/L) to a median value of 15 mg/L (range, 2-111 mg/L) at 12 hours postoperatively, which peaked at 48 hours to a median value of 125 mg/L (range, 22-247 mg/L). At 4 days postoperatively, CRP levels had declined to a median value of 69 mg/L (range, 21-234 mg/L). At 2 weeks, CRP had reached a median value of 12 mg/L (range, 1-72 mg/L), which was still higher than the baseline median value with available numbers (p < 0.001). CONCLUSIONS: We found that after uncomplicated TKA, IL-6 showed a sharp rise to peak at 12 hours, then fell rapidly to near baseline levels by 4 days and returned to the baseline level at 2 weeks. CRP showed a gradual rise to peak at 48 hours, then fell gradually, remaining elevated at 4 days and higher than baseline level at 2 weeks. Future studies can help define more definitive thresholds for IL-6 and CRP; ideally, these should derive from large, multicenter studies. With such data, any deviation from a known normal trajectory can facilitate a quicker decision to perform knee aspiration to diagnose early PJI more promptly. LEVEL OF EVIDENCE: Level III, diagnostic study.