In Jun Koh

How Effective Is Multiple Needle Puncturing for Medial Soft Tissue Balancing During Total Knee Arthroplasty? A Cadaveric Study

We investigated the quantitative effect and risk factors for over-release during multiple needle puncturing (MNP) for medial gap balancing in varus total knee arthroplasty (TKA). Of the ten pairs of cadaveric knees, one knee from each pair was randomly assigned to undergo MNP in extension (E group), while the other knee underwent MNP in flexion (F group). The increased extension and 90° flexion gaps after every five needle punctures were measured until over-release occurred. The extension gap (< 4mm) and the 90° flexion gap (< 6mm) gradually increased in both groups. The 90° flexion gaps increased more selectively than did the extension gaps. MNP in the flexed knee, a narrow MCL, and severe osteoarthritis were associated with a smaller number of MNPs required to over-release.

Trends in High Tibial Osteotomy and Knee Arthroplasty Utilizations and Demographics in Korea From 2009 to 2013

We analyzed the records of 29,895 high tibial osteotomies (HTOs), 12,589 unicompartmental knee arthroplasties (UKAs) and 363,386 total knee arthroplasties (TKAs) performed from 2009 to 2013 in Korea. They were compared with the latest nationwide registry reports of seven Western countries. Over the last 5 years, in Korea, the number of HTO, UKA and TKA increased by 210%, 138%, and 18%, respectively. The largest increase was observed in 55-64 year olds in HTO and UKA, while the largest increase in TKA was in ≥75 year olds. Females commonly had a three- to seven-fold higher rate in all procedures. Worldwide, the use of HTO and UKA decreased or remained stable, whereas that of TKA increased steadily, even in younger patients.

Incidence, Predictors, and Effects of Residual Flexion Contracture on Clinical Outcomes of Total Knee Arthroplasty

Patients who present with large flexion contracture (FC) but have well maintained maximum flexion tend to have a flexion-extension gap mismatch, which can cause residual FC or flexion instability after TKA. We routinely use posterior-stabilized implants, perform soft tissue balancing and additional distal femur resection, and determine the polyethylene insert thickness based on flexion-extension gap difference to avoid postoperative FC and flexion instability. We retrospectively reviewed 911 TKAs performed with this protocol to determine the incidence, predictors and effects of postoperative FC on clinical outcomes. Knees with postoperative FC ≥10° were identified, and their clinical outcomes were compared with knees without FC. The average follow-up period was 35months (range, 24-72months). Eighteen (2.0%) of the 911 knees presented with postoperative FC. The occurrence of postoperative FC was associated with preoperative FC and anterior knee pain, but not with a flexion-extension gap mismatch. A mild to moderate postoperative FC does not increase pain, but may be detrimental to quality of life.

How accurate are orthopedic surgeons in diagnosing periprosthetic joint infection after total knee arthroplasty?: A multicenter study

BACKGROUND The lack of standardized diagnostic criteria for periprosthetic joint infection (PJI) poses a challenge to accurate diagnosis of PJI. Recently, the Musculoskeletal Infection Society (MSIS) proposed diagnostic criteria for PJI. However, it is not known how well these proposed criteria accommodate real clinical scenarios. We determined what proportion of patients satisfied the MSIS criteria, and if MSIS criteria were not met, what other rationales were used to diagnose PJI. METHODS We retrospectively reviewed the records of 303 patients who underwent two-stage exchange arthroplasty for treatment of PJI of the knee at 17 institutions. The rationale for making the diagnosis of PJI was also recorded, if the case did not meet the MSIS criteria. In addition, detailed information about isolated microorganisms were gathered. RESULTS Among the 303 patients, 198 met the diagnostic criteria proposed by MSIS. Among the 105 patients who did not meet the MSIS criteria, 88% met two or three minor criteria; however joint fluid analysis or histologic analysis was not performed in 85% of these 105 patients. The most common rationale for the diagnosis of PJI was the presence of abnormal physical findings. Microorganisms were identified in only 52% of all patients; the most common organism was coagulase-negative Staphylococcus. CONCLUSIONS The diagnosis of PJI was based on clinical suspicion in approximately one-third of cases. In this series, joint aspiration or histological analysis was not performed in a large number of patients. Thus, surgeons should perform joint fluid and histologic analysis to assure the accuracy of PJI diagnosis.

Use of Reduced-Dose Periarticular Injection for Pain Management in Simultaneous Bilateral Total Knee Arthroplasty

We investigated the safety and efficacy of the bilateral periarticular multimodal drug injection (PMDI) at a reduced dosage in patients undergoing simultaneous bilateral total knee arthroplasty (SBTKA). In total, 45 patients undergoing SBTKA received 65 mL PMDI in each knee (reduced-dose group). The incidence of drug-related adverse effects and wound complications were evaluated. Pain levels during the night of the operation and postoperative day 1 and opioid consumption during the first 24 hours after surgery were compared with the regular-dose group of 55 patients undergoing SBTKA who received 100 mL of PMDI in 1 knee. No patient experienced a serious drug-related adverse effect or wound complication. Blood levels of ropivacaine were observed to be lower than a toxic level throughout the monitored period in all patients examined. Patients in the reduced-dose group experienced less pain during the night of operation, but a similar pain level at postoperative day 1.

Efficacy and Safety of a Novel Three-Step Medial Release Technique in Varus Total Knee Arthroplasty.

We investigated the efficacy and safety of our novel three-step medial release technique in varus total knee arthroplasty (TKA) over time. Two hundred sixty seven consecutive varus TKAs were performed by applying the algorithmic release technique which consisted of sequential release of the deep medial collateral ligament (step 1), the semimembranosus (step 2), and multiple needle puncturing of the superficial medial collateral ligament (step 3). One hundred seventeen, 114, and 36 knees were balanced after step 1, 2, and 3 releases, respectively. There were no significant differences in changes of medial and lateral laxities between groups in over a year. Our novel stepwise medial release technique was efficacious and safe in balancing varus knees during TKA.

Two- to Four-Year Follow-up Results of Total Knee Arthroplasty Using a New High-Flexion Prosthesis

Purpose The purpose of this study was to evaluate minimum 2-year follow-up results of total knee arthroplasty (TKA) performed using a new high-flexion prosthesis design (LOSPA). Materials and Methods The 2- to 4-year results of 191 consecutive TKAs (177 patients) with the LOSPA posterior-stabilized prosthesis were evaluated. The patients were assessed clinically and radiographically using the Knee Society scoring system (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results The mean range of motion (ROM) increased significantly from 117.4° (range, 75° to 140°) preoperatively to 126.7° (range, 80° to 144°) postoperatively (p<0.001). The mean KSS and WOMAC scores improved significantly from 121.4 (range, 42 to 185) and 56.1 (range, 23 to 88) preoperatively to 174.0 (range, 130 to 200) and 16.4 (range, 0 to 85) postoperatively, respectively (both, p<0.001). One knee required revision for deep infection. No knee had aseptic loosening or osteolysis. Radiolucent lines were noted in 15 knees (7.9%). Conclusions The new high-flexion total knee prosthesis resulted in no early aseptic loosening of the component and improved postoperative ROM comparable to other high-flexion TKA prostheses at 2- to 4-year follow-ups.

The Patient’s Age and American Society of Anesthesiologists Status Are Reasonable Criteria for Deciding Whether to Perform Same-Day Bilateral TKA

We investigated whether basing a decision to perform same-day bilateral TKA (SD BTKA) on the patients age and American Society of Anesthesiologists (ASA) status was reasonable. We retrospectively reviewed the records of 1386 patients who underwent 2086 TKAs (686 unilateral TKAs [UTKAs], 1038 SD BTKAs, and 362 one-week staged BTKAs). For the entire cohort, patients undergoing SD BTKA had a higher risk of major complications compared to those undergoing UTKA. However, there was no difference in the incidence of complications for patients aged<75 years with an ASA status of 1 or 2 who underwent UTKA or SD BTKA. If patients are selected based on age and ASA status, SD BTKA may have a risk of postoperative complication similar to UTKA.

The Patient's Perception Does Not Differ Following Subvastus and Medial Parapatellar Approaches in Total Knee Arthroplasty: A Simultaneous Bilateral Randomized Study

This simultaneous bilateral randomized study investigated whether patients would perceive the difference between the subvastus approach (SVA) and the medial parapatellar approach (MPA) after total knee arthroplasty (TKA). In 50 patients scheduled to undergo same-day bilateral TKA, one knee was randomly assigned to SVA and the other to MPA. Patient-reported measures (pain, Western Ontario McMaster University Osteoarthritis Index score, and side preference) and physician-assessed measures (isokinetic muscle strength, range of motion, and Knee Society score) were compared. No differences were observed in the patient-reported measures and physician-assessed measures, with the exception of greater quadriceps strength at postoperative 1 week in knees that underwent SVA. Patients receiving contemporary perioperative management after same-day bilateral TKA do not perceive any difference between knees that underwent SVA or MPA.

Is High-Flexion Total Knee Arthroplasty a Valid Concept? Bilateral Comparison With Standard Total Knee Arthroplasty

BACKGROUND The purpose of this study was to determine whether the high-flexion total knee prosthesis significantly improves knee flexion in vivo. METHODS Forty-four patients undergoing same-day bilateral total knee arthroplasty for primary osteoarthritis of both knees were randomized to receive a standard posterior-stabilized knee prosthesis (P.F.C. Sigma; DePuy Johnson & Johnson, Warsaw, IN) in one knee and a high-flexion concept posterior-stabilized knee prosthesis (LOSPA; Corentec, Inc, Seoul, Korea) in the other knee and were followed up for 2 years postoperatively. RESULTS The mean postoperative range of motion was 128.8° (range, 100°-144°) in the LOSPA group and 128.5° (range, 100°-142°) in the P.F.C. Sigma group (P = .744). There were no significant differences in the postoperative mean Knee Society score and Western Ontario and McMaster Universities Osteoarthritis Index score between the LOSPA and P.F.C. Sigma groups (P = .839 and P = .972, respectively). CONCLUSION Despite theoretical range of motion advantages of high-flexion prosthesis, there were no group differences with regard to range of motion, clinical outcomes, and the incidence of radiolucent lines at final follow-up assessment.