Internal rotation of the tibial component in total knee arthroplasty can lead to extension deficit.

PURPOSE: Stiffness is a common problem following total knee arthroplasty (TKA). Mal-rotated components have been claimed to be the major cause of pain and limited motion after TKA. The present study investigates whether intra-operative intentional malrotation of the tibial component would change in vivo kinematics. The hypothesis is excessive internal rotation of the tibial component would result in postoperative extension deficit. METHODS: Thirty-one patients were enrolled in this study. After completing bony cuts and proper soft tissue balancing, the femoral and tibial trials were impacted and fixed using small pins. Lateral radiographs were used to measure and compare intraoperative full knee extension during normal and after intentional internal rotation of the tibial component. The extension deficit angles were also compared between the posterior stabilised (PS) and cruciate retaining (CR) implants. RESULTS: For normal tibial component rotation, the median (interquartile range) extension deficit was 0° (4). The mean tibial trial intentional internal rotation was 21.2° (± 4.5). The median (interquartile range) extension deficit significantly increased to 6° (4) after tibial component internal rotation (p = 0.001). The use of PS spacers resulted in a significantly greater extension deficit after intentional internal rotation 9° (5) compared to that of the CR implant 1° (4) (p = 0.001). CONCLUSION: Internal rotation of the tibial component in total knee arthroplasty can lead to postoperative extension deficit. This could be attributed to interference with "screw home" mechanism that requires full external rotation of the tibia on the femur. Consequently, this deficit may cause pain and knee stiffness following TKA. LEVEL OF EVIDENCE: III.

Persistent Wound Drainage among Total Joint Arthroplasty Patients Receiving Aspirin vs Coumadin.

BACKGROUND: Persistent wound drainage (PWD) is one of the major risk factors for periprosthetic joint infections (PJI), arguably the most dreaded complications after a total hip and knee arthroplasty (THA and TKA). The aim of this study is to identify the rates of PWD among THA and TKA patients who received aspirin (ASA) or Coumadin for postoperative venous thromboembolism (VTE) prophylaxis. METHODS: Retrospective review of 5516 primary THA and TKA was performed. Patients with PWD were identified. Chi-square test was used to compare the incidences of PWD, 30-day VTE, and PJI at 6 months between the ASA and Coumadin groups. Multivariate regression model was used to identify independent risk factors for PWD using Charlson and Elixhauser comorbidity indexes. RESULTS: The prevalence of PWD was 6.4% (353/5516). Patients receiving ASA had lower incidence of PWD (3.2% vs 8.5%, P < .0001) while having comparable rates of 30-day VTE (1.3% vs 1.4%, P = .722) and PJI at 6 months (1.8% vs 1.4%, P = .233) compared to those receiving Coumadin. Risk factors for PWD were diabetes (odds ratio [OR], 19.3; 95% confidence interval [CI], 11.8-23.2), rheumatoid arthritis (OR, 15.3; 95% CI, 10.8-17.2), morbid obesity (OR, 13.2; 95% CI, 9.7-17.5), chronic alcohol use (OR, 3.5; 95% CI, 1.8-5.5), hypothyroidism (OR, 1.9; 95% CI, 1.1-3.2), and Coumadin (OR, 1.7; 95% CI, 1.2-2.2). CONCLUSION: Use of ASA is associated with significantly lower rates of PWD after THA and TKA when compared to Coumadin while being equally efficacious at preventing VTE. Coumadin was found to be an independent risk factor for PWD.

Comparing the Effect of Tourniquet vs Tourniquet-Less in Simultaneous Bilateral Total Knee Arthroplasties.

BACKGROUND: Total knee arthroplasty (TKA) is a commonly performed procedure worldwide for the treatment of knee joint disease. Tourniquet is frequently used during the entire procedure to reduce blood loss and increase surgical comfort. On the other hand, tourniquet-related complications exist, and there are still controversies whether benefits outweigh the risks. METHODS: Patients undergoing simultaneous TKAs had one knee assigned to group A (use of tourniquet during the entire procedure) and the other knee assigned to group B (use of tourniquet only during cementation). Blood loss, intraoperative complications, implant alignment, soft tissue swelling, pain score, and range of motion were analyzed. RESULTS: Fifty-four patients undergoing 108 TKAs were included in the study. Total blood loss was almost 2 times higher in group B knees compared with group A. No difference was observed between groups in implant alignment, soft tissue swelling, pain, range of motion, or other early postoperative complications. CONCLUSION: Tourniquet use in TKAs during the entire surgical procedure reduces total blood loss, without an increase in early postoperative complications.

Posterolateral overhang affects patient quality of life after total knee arthroplasty.

PURPOSE: To investigate the appropriate mediolateral placement of symmetrical tibial components and the amount of overhang expected from the posterolateral of tibial components implanted to give ideal coverage and the subsequent incidence of residual knee pain and reduction in functional capacity. METHOD: A retrospective evaluation was made of 146 consecutive total knee arthroplasties. The posterolateral overhang, rotational alignment and coverage of the tibial component were measured on a post-operative CT scan and the effect of posterolateral overhang on clinical outcomes was analysed 3 years after surgery. RESULTS: Complaints of local pain in the posterolateral corner were determined in 76 (52.1%) patients. At the Posterolateral corner, overhang was determined in 111 (76%) patients, in the cortical border in 11 (7.6%) patients and underhang in 24 (16.4%) patients. In 71 (48.6%) patients, pain was determined together with oversize and in the evaluation of the overhang of the tibial component in the posterolateral region and the rotation status, there was determined to be overhang in 75 (96.2%) patients where the tibial component was placed in ideal rotation, in 25 (100%) where placement was in external rotation and in 11 (25.6%) where placement was in internal rotation. The mean KSS, KSS-F and WOMAC-P scores were 83.9 ± 6.3, 83.3 ± 7.8 and 4.6 ± 2.9, respectively, in those with posterolateral overhang of the tibial component .The mean KSS, KSS-F and WOMAC-P scores were 86.6 ± 8.4, 89.5 ± 7.8 and 2.8 ± 2.1, respectively, in those with no overhang and the difference was determined to be statistically significant. The amount of overhang was determined as mean 3.6 ± 2.0 mm in those with posterolateral pain and 0.02 ± 3.4 mm in those without pain and the difference was statistically significant. CONCLUSIONS: This study demonstrated that overhang in the posterolateral region is surprisingly high and negatively affects the clinical results following TKA, thereby presenting a danger to the success of TKA. The risk of posterolateral oversizing can increase with placement of the tibial component in external rotation.

A Unique Pattern of Peri-Prosthetic Fracture Following Total Knee Arthroplasty: The Insufficiency Fracture.

An isolated periprosthetic compression fracture following total knee arthroplasty has not been described in periprosthetic fracture classifications. Thus, the purpose is to describe this unique type of fracture based on clinical and radiographic analysis and identify the incidence and potential risk factors of this fracture. A retrospective chart review was performed from a database of 5864 primary total knee. A total of 56 (0.9%) periprosthetic fractures were identified with 15 (26.8%) of them demonstrating an isolated lateral compression fracture. Patients exhibiting this fracture pattern had a mean preoperative varus deformity of 176.3° and had poor bone quality (T score: -2.1). It is important to recognize that a compression fracture is not an infrequent finding and that further workup maybe warranted when clinical suspicion is high.

Primary Repair of Iatrogenic Medial Collateral Ligament Injury During TKA: A Modified Technique.

Intraoperative injury to the medial collateral ligament (MCL) is a rare but important complication of total knee arthroplasty (TKA). While described treatment methods are mainly primary repair and revision with a more constrained implant, a few studies have investigated the outcomes of primary repair without constrained implants. A retrospective study was performed to evaluate the prevalence of iatrogenic injury to the MCL during primary TKA and determine the clinical outcomes of MCL repair augmented with synthetic material without the use of a constrained device. The incidence of intraoperative tear of the MCL was 0.43% (15/3432). No patient demonstrated instability during the follow-up period. Primary repair of iatrogenic MCL injury without the use of constrained implants appears to be a potential alternative that warrants further investigation.

Anatomic tibial component design can increase tibial coverage and rotational alignment accuracy: a comparison of six contemporary designs.

PURPOSE: The aim of this study was to comprehensively evaluate contemporary tibial component designs against global tibial anatomy. We hypothesized that anatomically designed tibial components offer increased morphological fit to the resected proximal tibia with increased alignment accuracy compared to symmetric and asymmetric designs. METHODS: Using a multi-ethnic bone dataset, six contemporary tibial component designs were investigated, including anatomic, asymmetric, and symmetric design types. Investigations included (1) measurement of component conformity to the resected tibia using a comprehensive set of size and shape metrics; (2) assessment of component coverage on the resected tibia while ensuring clinically acceptable levels of rotation and overhang; and (3) evaluation of the incidence and severity of component downsizing due to adherence to rotational alignment and overhang requirements, and the associated compromise in tibial coverage. Differences in coverage were statistically compared across designs and ethnicities, as well as between placements with or without enforcement of proper rotational alignment. RESULTS: Compared to non-anatomic designs investigated, the anatomic design exhibited better conformity to resected tibial morphology in size and shape, higher tibial coverage (92% compared to 85-87%), more cortical support (posteromedial region), lower incidence of downsizing (3% compared to 39-60%), and less compromise of tibial coverage (0.5% compared to 4-6%) when enforcing proper rotational alignment. CONCLUSIONS: The anatomic design demonstrated meaningful increase in tibial coverage with accurate rotational alignment compared to symmetric and asymmetric designs, suggesting its potential for less intra-operative compromises and improved performance. LEVEL OF EVIDENCE: III.

Tranexamic acid to reduce blood loss after bilateral total knee arthroplasty: a prospective, randomized double blind study.

The effects of 2-dosage regimens of tranexamic acid (10 mg/kg and 15 mg/kg) on blood loss and transfusion requirement were compared to saline placebo in 60 patients undergoing concurrent bilateral total knee arthroplasty, with additional reinfusion autotransfusion from intraarticular drains. Mean blood loss was 462 mL in 15 mL/kg group, 678 mL in 10 mg/kg group, and 918 mL in controls (P < .01 vs 15 mg/kg). Blood available for autotransfusion was greatest in controls and least in 15 mg/kg group. Combined autologous and allogenic transfusion volumes were similar in the treatment groups and significantly less than controls (P < .01). With use of an autologous reinfusion strategy, the lower dose is sufficient to lead to a lesser allogenic transfusion requirement.

Knee kinematics of high-flexion activities of daily living performed by male Muslims in the Middle East.

Full flexion is critical for total knee arthroplasty (TKA) patients in the Middle East, where daily activities require a high range of motion in the lower limb. This study aimed to increase understanding of the knee kinematics of normal Muslim subjects during high-flexion activities of daily living, such as kneeling, Muslim prayer, sitting cross-legged, and squatting. The early postoperative kinematics for a select group of Muslim, high-flexion TKA patients are also reported. Mean curves were compared between the normal group and the TKA group. During kneeling, the average maximum flexion was 141.6° for the normal group and 140.2° for the TKA group. The normal group's maximum and minimum knee angles (flexion, abduction, external rotation) were reported and, with the exception of maximum extension, were not significantly different from the TKA group, despite short postoperative times.

Can an anterior quadriceps release improve range of motion in the stiff arthritic knee?

We hypothesize that tethering adhesions of the quadriceps muscle are the major pathological structures responsible for a limited range of motion in the stiff arthritic knee. Forty-two modified quadriceps muscle releases were performed on 24 patients with advanced osteoarthritis scheduled for total knee arthroplasty. The ranges of motion were documented intraoperatively both before and immediately after the release. Passive flexion improved significantly in all patients (mean, 32.4 degrees of improvement, P < .001) following a modified quadriceps release, despite any presence of osteophytes or severe deformities. These results strongly implicate adhesions of the quadriceps muscle to the underlying femur, which prevent the distal excursion of the quadriceps tendon, as the restrictive pathology preventing deep flexion in patients with osteoarthritis.

Achieving deep flexion after primary total knee arthroplasty.

Total knee arthroplasty patients often have difficulty performing activities involving flexion beyond 130 degrees. The NexGen LPS Flex (Zimmer Inc, Warsaw, Ind) mobile bearing implant accommodates up to 155 degrees of flexion. Two hundred eighteen total knee arthroplasties were performed using this implant on 125 patients over a 2-year period with a minimum of 5 years follow-up. All data were collected prospectively. Forty-four percent of preoperative cases had full flexion (ie, 140 degrees active flexion and ability to kneel with thigh/calf contact for 1 minute). Five-year data showed an average flexion of 140 degrees +/- 11.5 degrees and flexion greater than 140 degrees in 103 knees (68%). There were no differences in patellofemoral pain levels, complications, or Knee Society scores despite our patients having, on average, an increase in flexion and function.