Results of a Highly Porous Metal-Backed Cementless Patella Implant: A Minimum 5-Year Follow-Up

Initial design cementless metal-backed patellar implants failed due to multiple reasons including implant design, use of first-generation polyethylene, and surgical technique. This study evaluates clinical outcomes and survivorship of total knee arthroplasty (TKA) using a current generation highly porous metal-backed patellar component. One-hundred twenty-five consecutive primary cementless TKAs with a compression molded highly porous metal-backed patella were reviewed. One-hundred three TKAs (82.4%) with 5-year clinical and radiographic follow-up were available for review. These were matched with 103 consecutive TKAs using a cemented patella of the same implant design. The cementless cohort had a mean age of 65.5 years, body mass index (BMI) of 33.0, and follow-up of 64.4 months. Indications for cementless TKA were based on multiple factors including age, BMI, and bone quality. There were no revisions for loosening or mechanical failure of the cementless patella compared with two cemented patellae revised for aseptic loosening. Eight patients required revisions in the cementless cohort: three for prosthetic joint infection (PJI), two for instability, one periprosthetic femur fracture, one for patella instability, and one for extensor mechanism rupture. Five patients required revisions in the cemented cohort: two for aseptic patellar loosening, one for aseptic femoral loosening, one for PJI, and one for instability. All-cause survivorship at 5 years was 92.2 and 95.1% for the cementless metal-backed implant and cemented implant cohorts, respectively. Use of a compression molded highly porous metal-backed patella component demonstrated excellent clinical and radiographic results at 5-year follow-up. Longer follow-up is required to evaluate the ability of highly porous cementless patella implants to provide durable long-term fixation.

Results of Primary Total Knee Arthroplasty in Patients on Chronic Psychotropic Medications

BACKGROUND

Psychotropic medications are commonly used to treat several mental health conditions. The aim of this study was to determine the impact of psychotropic medications in patients undergoing primary total knee arthroplasty (TKA) with respect to postoperative opioid use, complications, patient-reported outcome measures, and satisfaction.

METHODS

This is a retrospective cohort study of 514 consecutive patients undergoing primary TKA. There were 120 patients (23.3%) who were excluded due to preoperative opioid usage. The remaining 394 patients had a minimum 1-year follow-up. Of those, 133 (34%) were on psychotropic medications preoperatively and were compared to the remaining 261 (66%) patients who were not on psychotropics. Clinical data, satisfaction, Knee Society (KS) scores, Western Ontario McMaster Universities Arthritis Index, Patient-Reported Outcomes Measurement Index Score, Forgotten Joint Scores, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, postoperative opioid medication usage, and complications were compared.

RESULTS

The study cohort (psychotropic medications) had significantly lower postoperative KS Function, KS Knee, Forgotten Joint Scores, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, Western Ontario McMaster Universities Arthritis Index, and Patient-Reported Outcomes Measurement Index Score compared to the control group. The study group had a lower overall satisfaction score (Likert scale 1 to 5) and a lower percentage of patients either satisfied or very satisfied (4.55 versus 4.79, P < .001; 92.0 versus 97.24%, P = .03, respectively). Postoperative opioid usage was significantly greater in the study group at both 6.4 weeks (range, 4 to 8) and 12-month follow-up (52.76 versus 13.33%, P < .001; 5.51 versus 0.39%, P = .002, respectively). There were no differences in complications and revisions between the groups.

CONCLUSIONS

Patients on psychotropic medications should be educated on the risk of increased opioid consumption, diminished satisfaction, and patient-reported outcome measures following primary TKA. Given the large number of patients on psychotropic medications undergoing TKA, additional studies are needed to further improve clinical outcomes in this group.

Cementless metal-backed patellar components in primary total knee arthroplasty using an implant of modern design

Aims

The use of cementless total knee arthroplasty (TKA) components has increased during the past decade. The initial design of cementless metal-backed patellar components had shown high failure rates due to many factors. The aim of this study was to evaluate the clinical results of a second-generation cementless, metal-backed patellar component of a modern design.

Methods

This was a retrospective review of 707 primary TKAs in 590 patients from a single institution, using a cementless, metal-backed patellar component with a mean follow-up of 6.9 years (2 to 12). A total of 409 TKAs were performed in 338 females and 298 TKAs in 252 males. The mean age of the patients was 63 years (34 to 87) and their mean BMI was 34.3 kg/m2 (18.8 to 64.5). The patients were chosen to undergo a cementless procedure based on age and preoperative radiological and intraoperative bone quality. Outcome was assessed using the Knee Society knee and function scores and range of motion (ROM), complications, and revisions.

Results

A total of 24 TKAs (3.4%) in 24 patients failed and required revision surgery, of which five were due to patellar complications (0.71%): one for aseptic patellar loosening (0.14%) and four for polyethylene dissociation (0.57%). A total of 19 revisions (2.7%) were undertaken in 19 patients for indications which did not relate to the patella: four for aseptic tibial loosening (0.57%), one for aseptic femoral loosening (0.14%), nine for periprosthetic infection (1.3%), one for popliteus impingement (0.14%), and four for instability (0.57%). Knee Society knee and function scores, and ROM, improved significantly when comparing pre- and postoperative values. Survival of the metal-backed patellar component for all-cause failure was 97.5% (95% confidence interval 94.9% to 100%) at 12 years.

Conclusion

The second-generation cementless TKA design of metal-backed patellar components showed a 97.5% survival at 12 years, with polyethylene dissociation from the metal-backing being the most common cause of patellar failure. In view of the increased use of TKA, especially in younger, more active, or obese patients, these findings are encouraging at mean follow-up of seven years.

Does Preoperative Opioid Consumption Influence Patient Satisfaction following Total Knee Arthroplasty?

Chronic opioid use prior to total knee arthroplasty (TKA) has been implicated in adverse outcomes. The purpose of this study was to evaluate clinical outcome measures and patient satisfaction in patients with a history of preoperative chronic opioid use undergoing primary TKA. A retrospective cohort study was performed on 296 consecutive patients undergoing primary TKA. Seventy-four (25%) patients were identified with chronic preoperative opioid use (study group; 22 males, 52 females). A 3:1 matched cohort ratio of control versus study group was utilized resulting in a control group consisting of 222 patients (97 males, 125 females) without chronic opioid use prior to surgery. There was no statistically significant difference in age, BMI, or follow-up. Average follow-up was 23.4 months in the control group and 23.6 months in the study group (p = 0.87). Clinical data including patient satisfaction (Likert score), Knee Society (KS) Knee scores, KS Function scores, Forgotten Joint Score (FJS), length of stay (LOS), and complications were evaluated. Patient satisfaction at the most recent visit was 92.8% in the control group versus 83.8% in the chronic opioid group (p = 0.0016). Differences in patient-reported outcomes measures comparing the control and study cohorts included KS Function Score of 83.23 versus 75.31 (p = 0.0034). The FJS of 63.7 versus 58 (p = 0.1883) and the KS Knee Score of 89.5 versus 88.1 (p = 0.4075) were not significant. Postoperative opioid usage for the control versus the study group was 62/222 (27.9%) versus 56/74 (75.7%) at 4 to 8 weeks (p <0.0001), and 4/222 (1.80%) versus 27/74 (36.5%) at 12 months (p <0.0001). Overall complication occurrence was 18.9% in the study group versus 11.3% in the control group (p = 0.11). Patients with history of chronic preoperative opioid use had significantly lower patient satisfaction and KS Function scores and increased postoperative opioid usage at 12 months compared with patients without a history of opioid use prior to TKA.

Is There a Difference in PROMs Between Morbidly Obese Patients and Nonobese Patients Following Primary Total Knee Arthroplasty?

Background

Patient satisfaction and patient-reported outcome measures (PROMs) are important for patients, surgeons, and payers in the current healthcare climate. Morbidly obese patients (body mass index [BMI] >40) have demonstrated higher incidence of complications after total knee arthroplasty (TKA) and can have difficulty obtaining access for their surgical care. The purpose of this study was to evaluate PROMs and patient satisfaction in morbidly obese patients undergoing primary TKA.

Methods

A total of 75 patients with BMI >40 kg/m² undergoing robotic-assisted TKA were retrospectively identified and matched 2:1 to a consecutive cohort of patients with BMI <35. The average BMI of the study cohort was 42.4 kg/m² (39.5-51.3) compared to 28.6 kg/m² (18.5-34.9) in the control group. Clinical outcomes, PROMs, and patient satisfaction were evaluated at a minimum 2-year follow-up.

Results

The patients of the BMI >40 cohort were less likely to be discharged home (P = .0076), had less active flexion at 2 years (P = .0046), and had worse knee scores at 2 years (0.0497). Despite this, the percentage of patients who were satisfied or very satisfied after surgery was similar between the groups (87.5% vs 91.2%, P = .1943).

Conclusions

Morbidly obese patients are less likely to be discharged directly to home and may have functional differences after primary TKA. However, morbidly obese patients have similar PROMs and are as satisfied as nonobese patients at 2 years. Morbidly obese patients with end-stage knee osteoarthritis should also be able to enjoy the benefits of primary TKA following medical and surgical optimization.

Cementless Metal-Backed Patellar Components in Primary Total Knee Arthroplasty: An Average 10-Year Follow-Up

BACKGROUND

Historically, 1st generation metal-backed cementless patellar implants demonstrated high failure rates due to multiple factors. The 2nd generation cementless implants were developed with purported improvements in component design and polyethylene wear characteristics. This study evaluated clinical results of a current generation cementless metal-backed patellar implant with a minimum 5-year follow-up.

METHODS

One hundred and thirty-six primary total knee arthroplasties (TKAs) with metal-backed cementless patellae were compared to 183 cemented patellae with the same implant design. The cementless group mean age was 61 years (range, 40 to 81), mean body mass index (BMI) of 34.9 (range, 22.6 to 64.5), and mean follow-up of 10 years (range, 5 to 13). The cemented group mean age was 65 years (range, 32 to 89), mean BMI of 32.5 (range, 18.2 to 56.6), and mean follow-up of 10 years (range, 5 to 12). Significant demographic differences of age (P < .001), BMI (P < .01), and sex (P < .001) were found, with cementless patients being younger, heavier, and with more men.

RESULTS

There were no statistical differences in non-revision procedures (P = .214), TKA revisions (P = .639), patellar revisions (P = .151), and patellar aseptic loosening (P = .737). The 10-year survivorship of the cementless metal-backed patella was 95.9% with all-cause failure as the endpoint. The 10-year survivorship of the cemented patellar component was 98.9%.

CONCLUSION

This study demonstrated noninferiority of a 2nd generation HA-coated cementless metal-backed patellar implant in primary TKA compared to cemented patellae with 10-year survivorship of 95.9%. Advances in implant design and polyethylene wear properties have led to improved clinical results with metal-backed patellar components in primary TKA.

"Incidence of Instability Following Primary Total Hip Arthroplasty Continues to Decline in the Medicare Population"

BACKGROUND

Instability has been the primary cause of failure following primary total hip arthroplasty (THA) leading to revision hip surgery. The purpose of this study was to determine if instability rates have further declined following advances in primary THA including dual mobility articulations, direct anterior approaches, advanced technologies, and improved knowledge of the hip-spine relationships.

METHODS

Using the 5% Medicare Part B claims data from 1999 to 2019, we identified 81,573 patients who underwent primary THA for osteoarthritis. Patients who experienced instability at 3 months, 6 months, 1 year, and 2 years were identified. Multivariate cox regression analyses evaluated the effect of patient and procedure characteristics on the risk for instability.

RESULTS

Instability at 1 year following primary THA declined from approximately 4% in 2000 to 2.3% in 2010 and 1.6% in 2018. The leading cause of revision surgery was infection (18.6%), followed by peri-prosthetic fracture (14%), mechanical loosening (11.5%), and instability (9.4%). High risk groups for instability continue to include increased age, higher Charlson index, obesity, lumbar spine pathology, and neurocognitive disorders.

CONCLUSION

Instability is no longer the leading etiology of failure following primary THA with a decline of approximately 40% over the past decade. Infection, periprosthetic fracture, mechanical loosening, and then instability are now the leading causes of failure. Multiple factors may play a role in the decline of instability including increased use of dual mobility articulations, direct anterior approaches, improved knowledge of the hip-spine relationships, and use of advanced technologies.

Primary THA Using Thin Polyethylene Liners and Large Femoral Heads: A Minimum 5-Year Follow-Up

BACKGROUND

Large femoral head sizes are commonly used in total hip arthroplasty (THA) to minimize the risk of instability. With small acetabular cup-size, large femoral head diameter often results in the use of thin polyethylene liners. The purpose of this study was to evaluate clinical and radiographic results of large femoral heads against thin polyethylene liners with minimum 5-year follow-up.

METHODS

This was a retrospective review identifying 58 primary THAs utilizing thin polyethylene inserts from one manufacturer (X3 polyethylene, Stryker, Mahwah, NJ) and large femoral heads (36 mm or greater) with minimum 5-year follow-up. A total of 3 patients were deceased and 11 lost to follow-up, leaving 44 patients for review. All patients were female with mean age 65.7 (range 26-85) and mean body mass index (BMI) 29.9 (range 19.6-45.4). Average length of follow-up was 8.5 years (range 5.1-11.3). Outcome measures included survivorship, complications, PROMs and radiographic analysis.

RESULTS

There were four revisions: two aseptic loosening, one prosthetic joint infection, and one recurrent dislocation. Average HOOS-Jr, FJS-12, and patient satisfaction using Likert score was 94.3/100, 92.9/100, and 4.69/5.00, respectively, with 94% of patients reporting being satisfied or very satisfied. Radiographic analysis at average of 8.5 years demonstrated well-fixed implants without evidence of progressive radiolucent lines, osteolysis, or failure of the polyethylene liner. Survivorship using failure of the thin polyethylene liner as the endpoint was 100% at an average of 8.5 years.

CONCLUSION

Thin polyethylene liners used with large femoral head sizes in small acetabular cups demonstrated excellent results at average 8.5-year follow-up with no cases of liner fracture or osteolysis.

Cementless Total Knee Arthroplasty Using a Highly Porous Tibial Baseplate in Morbidly Obese Patients: Minimum 5-Year Follow-Up

BACKGROUND

 Morbidly obese patients undergoing cemented primary total knee arthroplasty (TKA) can pose a challenging problem with implant survivorship due to greater stress at the cement-bone interface. With the advent of additive manufacturing (three-dimensional printing), highly porous implants are now readily available. The purpose of this study was to review the results of primary TKA in the morbidly obese (body mass index [BMI] ≥ 40) patient using a highly porous cementless tibial baseplate.

METHODS

 This is a retrospective study of 167 TKAs in patients with morbid obesity undergoing primary cementless TKA with a minimum 5-year follow-up. A total of 6 patients died and 14 were lost to follow-up, leaving 147 TKAs in 136 patients with a mean follow-up of 66 months (range 60-79 months). The average age was 59 years (range 36-84 years) and average BMI was 45 kg/m² (range 39.5-63.9). Clinical results, patient-reported outcome measures, radiographs, and complications were reviewed.

RESULTS

 There were 9 failures requiring revision, including 3 for aseptic tibial loosening (2.0%), 2 for deep infection (1.4%), 2 for patellar resurfacing (1.4%), 1 for patella instability (0.7%), and 1 for extensor mechanism rupture (0.7%). Knee Society Score (KSS) improved from 48 to 90 at 2- and 5-year follow-up. KSS function score improved from 49 to 68 and 79 at 2- and 5-year follow-up, respectively. Survivorship with aseptic loosening as the endpoint was 98.0% at 5 years.

CONCLUSION

 Cementless TKA using a highly porous tibial baseplate in morbidly obese patients demonstrated excellent clinical results with 98% survivorship at 5 years and appears to offer durable long-term biologic fixation as an alternative to mechanical cement fixation in this challenging group of patients.

Results of Cemented Posterior-Stabilized Total Knee Arthroplasty in Obese Patients With an Average 10-Year Follow-Up

BACKGROUND

Obese and morbidly obese patients undergoing primary total knee arthroplasty (TKA) place significant stress at the bone-cement-implant interface over the life of the patient. The purpose of this study is to evaluate results of cemented, posterior-stabilized TKA in obese and morbidly obese patients at an average follow-up of 10 years.

METHODS

Retrospective study of 181 patients who had a cemented, posterior-stabilized TKA between 2000 and 2013 with body mass index >35 at the time of surgery was conducted. Clinical data and radiographs were evaluated along with survivorship, complications, and revisions. Minimum follow-up was 5 years with an average follow-up of 10 years.

RESULTS

There were 135 women and 46 men in the study, with mean age of 60.2 years (range 43-80), mean body mass index of 42.0 (range 35.1-66.1), and an average follow-up of 10 years (range 5-18). There were a total of 39 failures (22%) that underwent revision TKA surgery with mean time to revision of 8 years. Failures included 25 (14%) cases of aseptic loosening; 9 (5%) polyethylene wear; 2 (1%) prosthetic joint infection; and 3 additional revisions for instability, pain, and stiffness. There were a total of 11 cases of isolated tibial component loosening and 13 for both tibial and femoral loosening. Survivorship at 15 years with aseptic loosening as the endpoint was 86.7%, and for all causes 79.6% at 15 years.

CONCLUSION

Aseptic loosening is the leading cause of failure following TKA in obese and morbidly obese patients with decreasing survivorship from 96.1% to 91.2% and 86.7% at 5, 10, and 15 years, respectively.

Understanding Nail Gun Injuries in Orthopedics: Mechanisms and Treatment

Nail gun injuries are common among users, and most frequently involve the hands and lower extremities. A wide variation in costs and time are missed from work due to these injuries, and training on the proper use of nail guns has been shown to decrease workplace-related injuries. Minimal long-term disability can be expected, and orthopedic evaluations provide an opportunity to inform patients on proper use of these devices. In this article, management of nail gun injuries is discussed, including the necessity for a high suspicion for wound contamination because foreign material is often deposited with the nail, as well as treatment with debridement and antibiotics. [Orthopedics. 2019; 42(5):e410-e414.].

Massive Gluteal Muscle Necrosis after Iliac Arterial Embolization in Pelvic Trauma: A Literature Review and Illustrative Case Report

Introduction:

Traumatic pelvic injuries causing retroperitoneal bleeding can be managed with angiographic embolization. This procedure carries a small but potentially devastating risk of gluteal muscle necrosis.

Case Report:

An 18-year-old trauma patient suffered from massive gluteal muscle necrosis following angiographic embolization for hemorrhage from pelvic fracture was reported.

Conclusion:

To limit morbidity and mortality, the orthopedic surgeon should have a high suspicion for gluteal muscle necrosis to allow for early diagnosis and then treatment with decompression and debridement.

Results of Cemented vs Cementless Primary Total Knee Arthroplasty Using the Same Implant Design

BACKGROUND

Although cemented total knee arthroplasty (TKA) continues to be the gold standard, there are patient populations with higher failure rates with cemented TKAs such as the obese, morbidly obese, and younger active males. Cementless TKA usage continues to increase because of the potential benefits of long-term biologic fixation similar to the rise in cementless total hip arthroplasty. The purpose of this study was to evaluate the clinical and radiographic results of cementless TKA using a novel highly porous cementless tibial baseplate.

METHODS

This was a retrospective matched case-control study of 400 primary TKAs comparing cementless vs cemented TKAs using the same implant design (Stryker Triathlon; Stryker Inc, Mahwah, NJ). Two-hundred patients with a mean age of 64 years (range 42-88 years) and body mass index (BMI) of 33.9 kg/m² (range 19.7-57.1 kg/m²) were matched to 200 primary cemented TKA patients with a mean age of 64 years (range 43-87 years) and BMI of 33.1 kg/m² (range 22.2-53.2 kg/m²). The mean follow-up in the cementless group was 2.4 years (range 2-3.5 years) and in the cemented group was 5.3 years (range 2-10.9 years). Clinical and radiographic analyses were evaluated. Statistical analysis was performed using the Microsoft Excel, version 15.21.1.

RESULTS

There was no statistical difference in age, BMI, and preoperative Knee Society Scores between the 2 groups (P = .22, P = .82, and P = .43, respectively). Patients in both groups had a similar incidence of postoperative complications (P = .90). Cementless group had 7 revisions with one aseptic loosening of the tibial component (0.5%). Cementless tibial baseplates demonstrated areas of increased bone density at the pegs of the tibial baseplate. The cemented group had 8 total revisions with 5 cases of aseptic loosening (2.5%).

CONCLUSION

Early results of cementless TKA using a highly porous tibial baseplate designed with a keel and 4 pegs appear promising with one case of aseptic loosening at minimum 2-year follow-up. As the demographics of patients undergoing TKA change to include younger, obese, and more active patients, along with increased life expectancy, the use of a highly porous cementless tibial baseplate may be beneficial in providing long-term durable biologic fixation similar to the success of cementless total hip arthroplasty.

Comparison of intravenous versus topical tranexamic acid in total knee arthroplasty: a prospective randomized study

The purpose of this study was to compare the efficacy of topical Tranexamic Acid (TXA) versus Intravenous (IV) Tranexamic Acid for reduction of blood loss following primary total knee arthroplasty (TKA). This prospective randomized study involved 89 patients comparing topical administration of 2.0g TXA, versus IV administration of 10mg/kg. There were no differences between the two groups with regard to patient demographics or perioperative function. The primary outcome measure, perioperative change in hemoglobin level, showed a decrease of 3.06 ± 1.02 in the IV group and 3.42 ± 1.07 in the topical group (P = 0.108). There were no statistical differences between the groups in preoperative hemoglobin level, lowest postoperative hemoglobin level, or total drain output. One patient in the topical group required blood transfusion (P = 0.342). Based on our study, topical Tranexamic Acid has similar efficacy to IV Tranexamic Acid for TKA patients.

Wear analysis of first-generation highly cross-linked polyethylene in primary total hip arthroplasty: an average 9-year follow-up

This is a retrospective review of 46 primary total hip arthroplasties using a first-generation highly cross-linked ultrahigh-molecular-weight polyethylene liner (Crossfire; Stryker, Mahwah, NJ) with an average of 9-year follow-up. The purpose of this study was to measure linear penetration rate of first-generation polyethylene to determine if it maintains its wear resistance and fatigue strength over an extended period compared with conventional polyethylene. The mean (SD) total penetration was 0.339 (0.204) mm, and the mean (SD) penetration rate was 0.037 (0.022) mm/y. Our study demonstrated a 74% reduction in total penetration of highly cross-linked polyethylene when compared with historical controls using conventional polyethylene at an average of 9 years. Our results support the belief that highly cross-linked polyethylene does retain its wear resistance over an extended period.

Decreased dislocation after revision total hip arthroplasty using larger femoral head size and posterior capsular repair

The purpose of this study was to determine if the use of both a larger femoral head size and a posterior capsular repair would lead to a decreased incidence of dislocation following revision total hip arthroplasty (THA). Two hundred forty-two consecutive revision THAs with posterolateral approach were performed between 2000 and 2005. Group 1 had 132 revision THAs with posterolateral approach and 28-mm head size without posterior capsule repair. Group 2 had 100 revision THAs with a 32-mm head size and repair of the remaining hip capsule. There were no statistically significant differences in the two groups. Group 1 had 14 dislocations (10.6%). Group 2 had 3 dislocations (2.7%) (P < .05). Based on the results of this retrospective review, the authors recommend the use of both larger femoral head sizes and repair of any posterior capsular tissue available in patients undergoing revision hip arthroplasty.