Postoperative Hemodynamics of Total Knee Arthroplasty Unaffected by Cementless Approach under Contemporary Patient Blood Management Protocol: A Propensity Score-Matched Study

(1) Background: A cementless total knee arthroplasty (TKA) is a recent and an increasingly popular innovation that enhances porous fixation surfaces. However, the lack of cemented sealing of an exposed resected bone has raised concerns about the potential for greater blood loss. The goals of this study were to determine if a cementless approach impacts post-TKA hemodynamics and to identify risk factors for blood loss in instances of cementless (vs. cemented) TKAs under a contemporary patient blood management (PBM) protocol. (2) Methods: We recruited 153 consecutive patients undergoing unilateral TKAs between 2019 and 2023. All enrollees received cementless or cemented prostheses of the same design (cementless, 87; cemented, 66). After propensity score matching for demographics, there were 46 patients in each group. We then compared blood loss metrics (total [TBL] and estimated [EBL]), drainage volumes, hemoglobin (Hb) levels, and transfusion rates by group. (3) Results: Post-TKA hemodynamics (i.e., TBL, EBL, drainage, Hb level, and transfusion rate) of cementless (n = 46) and cemented (n = 46) TKA groups did not differ significantly. In addition, the proportions of patients with Hb drops > 3.0 g/dL were similar for the two groups. A logistic regression analysis revealed that only preoperative Hb and EBL during the early postoperative period were predictive of a substantial fall in Hb levels. The fixation method was not associated with Hb decline > 3.0 g/dL by postoperative Day 3. (4) Conclusion: The cementless TKA has no impact on customary post-TKA hemodynamics and is not associated with greater TKA-related blood loss when implementing a contemporary PBM protocol.

No Blood Loss Increase in Cementless vs. Cemented Fixation Following Bilateral Total Knee Arthroplasty: A Propensity Score Matching Study

Background and Objectives: Recent advancements in three-dimensional printing technology have enhanced the biologic fixation of cementless total knee arthroplasty (TKA), therefore increasing the utilization of newer-generation cementless implants. However, the lack of sealing and tamponade effect of cement on the resected bone surface after cementless TKA raises concerns regarding the potential for greater blood loss compared to cemented TKA. The aim of this study was to (1) compare blood loss and transfusion rates between cementless and cemented TKAs and (2) identify the risk factor for higher blood loss in patients who underwent 1-week-interval staggered bilateral (SB) TKA. Materials and Methods: This retrospective, propensity-matched study included 54 cementless and 53 cemented SB TKAs performed by a single surgeon from 2019 to 2023 with a single implant that has similar design features in both cementless and cemented implants. All patients underwent 1-week-interval SB TKA and received the same patient blood management (PBM) and rehabilitation protocol. The estimated total blood loss (TBL), transfusion rate, and total hemoglobin drop were assessed. Patients were categorized according to TBL into average TBL and higher TBL groups. Univariate and multiple logistic regression analyses were performed to identify risk factors for higher blood loss. Results: There was no difference in TBL between cementless and cemented TKA groups (1233 ± 299 and 1282 ± 309 mL, respectively; p > 0.05). In addition, no between-group differences in the transfusion rate and mean total hemoglobin drop were observed. The logistic regression analyses revealed that whether TKA was cementless or cemented was not associated with higher blood loss; rather, the only identified risk factor was the pre-TKA patient blood volume (odd ratio 1.001, 95% confidence interval 1.000-1002, p = 0.026). Conclusions: Contemporary cementless fixation does not increase blood loss or transfusion rates compared to cemented fixation in patients undergoing 1-week-interval staggered bilateral TKA.

Mobile-Bearing has no Benefit Over Fixed-Bearing Total Knee Arthroplasty in Joint Awareness and Crepitus: A Randomized Controlled Trial

BACKGROUND

Given higher component conformity, rotational availability of polyethylene insert, and more physiologic patellofemoral tracking, mobile-bearing (MB) total knee arthroplasty (TKA) is supposed to offer advantages in joint perception and crepitus. The purpose of this study was to investigate whether MB TKA offers superior outcomes over fixed-bearing (FB) TKA in terms of joint awareness and crepitus.

METHODS

This prospective, randomized, controlled trial included 49 FB and 49 MB TKAs that shared the same posterior-stabilized femoral component. Primary outcomes included joint awareness assessed with the Forgotten Joint Score and crepitus graded according to severity and sound at 3 years postoperatively. Secondary outcomes were the range of motion, the Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index, component position, and joint line level on radiographs.

RESULTS

The Forgotten Joint Score showed no significant difference between the FB (67 points; range, 0-100) and MB groups (63 points; range, 13-100) (P = .440). For crepitus, no significant differences were found in the overall incidence rate (FB group, 18%; MB group, 12%; P = .386) and grade (grade 1, 6 versus 5; grade 2, 2 versus 1; grade 3, 1 versus 0, respectively). There were no significant differences in range of motion, Knee Society Score, and Western Ontario and McMaster Universities Osteoarthritis Index, as well as radiographic outcomes between the two groups (all, P > .05).

CONCLUSION

MB TKA offers no benefits in terms of joint awareness and crepitus compared with FB TKA at mean 3 years postoperatively. The theoretical advantages of MB TKA have yet to be demonstrated in practice, leaving the selection of bearing type to the surgeon's judgment.

LEVEL OF EVIDENCE

Level II.

Is the patient aware of the difference between resurfaced and nonresurfaced patella after bilateral total knee arthroplasty? A systematic review of simultaneous bilateral randomized trials

Purpose

The optimal practice of patellar management in total knee arthroplasty (TKA) remains controversial. This systematic review was conducted to compare patella-related (1) patient-reported outcome measures (PROMs), (2) clinical outcomes, and (3) reoperation rates after TKA with patellar resurfacing (PR) and nonresurfacing (NPR) in single patients undergoing bilateral patellar procedures during simultaneous bilateral TKA.

Methods

This review included prospective bilateral randomized trials investigating patella-related PROMs, clinical outcomes, and reoperation (secondary resurfacing and patellar component revision) and other patella-related complications in single patients undergoing randomly assigned PR and NPR during bilateral TKA.

Results

Six studies were included. There was no difference in PROMs between PR and NPR in five studies, whereas PR was found to be superior to NPR in one study. Five studies reported similar functional outcomes and complication rates between PR and NPR, while one study found better clinical outcomes and a lower complication rate in PR. Between-group secondary resurfacing and patellar revision rates were similar in all studies.

Conclusions

The majority of patients who underwent bilateral patellar procedures could not tell the difference between PR and NPR following bilateral TKA. There were no differences in clinical outcomes or reoperation and complication rates between PR and NPR. No evidence was found to support routine PR.

Level of evidence: Therapeutic Level 1

Guided-Motion Bicruciate-Stabilized Total Knee Arthroplasty Reproduces Native Medial Collateral Ligament Strain

Background and Objectives: Guided-motion bicruciate-stabilized (BCS) total knee arthroplasty (TKA) includes a dual cam-post mechanism with an asymmetric bearing geometry that promotes normal knee kinematics and enhances anterior-posterior stability. However, it is unclear whether the improved biomechanics after guided-motion BCS TKA reproduce soft tissue strain similar to the strain generated by native knees. The purpose of this cadaveric study was to compare medial collateral ligament (MCL) strain between native and guided-motion BCS TKA knees using a video extensometer. Materials and Methods: Eight cadaver knees were mounted onto a customized knee squatting simulator to measure MCL strain during flexion in both native and guided-motion BCS TKA knees (Journey II-BCS; Smith & Nephew, Memphis, TN, USA). MCL strain was measured using a video extensometer (Mercury® RT RealTime tracking system, Sobriety s.r.o, Kuřim, Czech Republic). MCL strain level and strain distribution during knee flexion were compared between the native and guided-motion BCS TKA conditions. Results: The mean and peak MCL strain were similar between native and guided-motion BCS TKA knees at all flexion angles (p > 0.1). MCL strain distribution was similar between native and BCS TKA knees at 8 of 9 regions of interest (ROIs), while higher MCL strain was observed after BCS TKA than in the native knee at 1 ROI in the mid portion of the MCL at early flexion angles (p < 0.05 at ≤30° of flexion). Conclusions: Guided-motion BCS TKA restored the amount and distribution of MCL strain to the values observed on native knees.

Restoration of the Joint Line Configuration Reproduces Native Mid-Flexion Biomechanics after Total Knee Arthroplasty: A Matched-Pair Cadaveric Study

Background: Recent evidence supports that restoration of the pre-arthritic condition via total knee arthroplasty (TKA) is associated with improved post-TKA performance and patient satisfaction. However, whether the restored pre-arthritic joint line simulates the native mid-flexion biomechanics remains unclear. Objective: We performed a matched-pair cadaveric study to explore whether restoration of the joint line via kinematically aligned (KA) TKA reproduced native knee biomechanics more accurately than the altered joint line associated with mechanically aligned (MA) TKA. Methods: Sixteen fresh-frozen cadaveric knees (eight pairs) were affixed onto a customized knee-squatting simulator for measurement of femoral rollback and medial collateral ligament (MCL) strain during mid-flexion. One knee from each cadaver was randomly designated to the KA TKA group (with the joint line restored to the pre-arthritic condition) and the other to the MA TKA group (with the joint line perpendicular to the mechanical axis). Optical markers were attached to all knees and rollback was analyzed using motion capture cameras. A video extensometer measured real-time variations in MCL strain. The kinematics and MCL strain prior to and following TKA were measured for all specimens. Results: KA TKA was better for restoring the knee kinematics to the native condition than MA TKA. The mid-flexion femoral rollback and axial rotation after KA TKA were consistently comparable to those of the native knee. Meanwhile, those of MA TKA were similar only at ≤40° of flexion. Furthermore, KA TKA better restored the mid-flexion MCL strain to that of the native knee than MA TKA. Over the entire mid-flexion range, the MCL strain of KA TKA and native knees were similar, while the strains of MA TKA knees were more than twice those of native knees at >20° of flexion. Conclusions: The restored joint line after KA TKA effectively reproduced the native mid-flexion rollback and MCL strain, whereas the altered joint line after MA TKA did not. Our findings may explain why patients who undergo KA TKA experience superior outcomes and more natural knee sensations during daily activities than those treated via MA TKA.

Changes in joint space width over time and risk factors for deterioration of joint space width after medial opening-wedge high tibial osteotomy

PURPOSE

The purpose of this study was to evaluate the changes in joint space width (JSW) over time after medial opening-wedge high tibial osteotomy (MOWHTO) and identify risk factors for deterioration of JSW using anteroposterior (AP) and Rosenberg views.

METHODS

We retrospectively analyzed changes in JSW of 104 MOWHTO patients whose preoperative osteoarthritis (OA) grade was K-L grade 3 or less on AP and Rosenberg views. Serial changes in JSW were assessed from preoperatively to at least 3 years postoperatively. Patients were divided into two groups according to JSW change patterns on each of AP and Rosenberg views: non-deterioration group had either unchanged or increased JSW, and deterioration group had decreased JSW. Clinical outcomes were compared using Western Ontario and McMaster Universities OA Index (WOMAC) score between groups. Multivariate logistic regression analysis was performed to identify risk factors for deterioration of JSW.

RESULTS

JSW on average for all patients increased 0.5 mm and 0.8 mm on AP and Rosenberg views, respectively (p < 0.05). Non-deterioration group showed significant improvement based on patient-reported outcomes (WOMAC) than deterioration group (all p < 0.05). Undercorrection was an independent risk factor for failure to achieve maintained or increased JSW on both AP (OR 6.885, 95% CI 1.976-23.986, p = 0.002) and Rosenberg (OR 12.756, 95% CI 2.952-55.129, p = 0.001) views.

CONCLUSION

JSW increased gradually and continuously on standing AP and Rosenberg views until postoperative 3 years after MOWHTO. Deterioration of JSW following MOWHTO was closely related to the undercorrection and affected clinical outcomes.

LEVEL OF EVIDENCE

Level III, case control study.

Kinematically aligned total knee arthroplasty restores more native medial collateral ligament strain than mechanically aligned total knee arthroplasty

PURPOSE

Kinematically aligned total knee arthroplasty (KA TKA) targets restoration of patient-specific alignment and soft tissue laxity. However, whether KA TKA reproduces native soft tissue strain remains unclear. This cadaveric study tested the hypothesis that KA TKA would better restore the quantitative strain and strain distribution of medial collateral ligament (MCL) to the native healthy knee compared to mechanically aligned (MA) TKA.

METHODS

Twenty-four fresh-frozen cadaver knees (12 pairs) were mounted on a customized knee squatting simulator to measure MCL strain during flexion. For each pair, one knee was assigned to KA TKA and the other to MA TKA. During KA TKA, the amount of femur and tibia resected was equivalent to implant thickness without MCL release using the calipered measuring technique. MA TKA was performed using conventional measured resection techniques. MCL strain was measured using a video extensometer (Mercury® RT RealTime tracking system, Sobriety s.r.o, Czech Republic). MCL strain and strain distribution during knee flexion were measured, and the measurements compared between native and post-TKA conditions.

RESULTS

Mean and peak MCL strain were similar between KA TKA and native knees at all flexion angles (p > 0.1 at all flexion angles) while mean strain at all flexion angles and peak strain at ≥ 60º of MA TKA were approximately twice those of the native knees (p < 0.05 at ≥ 60º of flexion). In addition, greater MCL strain was observed in 4 of 12 regions of interest (ROI) after MA TKA (M1, M2, P1 and P2) compared to the native knee, whereas after KA TKA, MCL strain measurements were similar at all but 1 ROI (P2).

CONCLUSIONS

KA TKA restored a more native amount and distribution of MCL strain compared to MA TKA. These findings provide clues for understanding why patients may experience better performance and more normal knee sensations after KA TKA compared to MA TKA.

LEVEL OF EVIDENCE

Therapeutic study, Level I.

Synergistic effect of the anterolateral ligament and capsule injuries on the knee laxity in anterior cruciate ligament injured knees: A cadaveric study

INTRODUCTION

There is much controversy about the practical role of the anterolateral ligament (ALL) and its relation to other anterolateral knee structures including the anterolateral capsule (ALC) and iliotibial band (ITB). The purpose of this cadaveric study was to investigate the effect of the ALL and ALC injuries on knee laxity with the iliotibial band (ITB) preserved in the anterior cruciate ligament (ACL)-injured knee.

HYPOTHESIS

The ALL and ALC would contribute to knee joint stability during anterior translation and internal rotation of the tibia in an ACL-injured knee.

MATERIAL AND METHODS

For 10 fresh-frozen cadaveric knees, we measured knee laxity with the following state of knee injuries with ITB preserved: (1) intact knee, (2) ACL-sectioned knee (ACL-), (3) additional sectioning of the ALL (ACL-/ALL-), and (4) additional sectioning of the ALC (ACL-/ALL-/ALC-). We did biomechanical measurements in internal-external rotation, anterior-posterior translation, and varus-valgus angulation for each condition at knee flexion angles of 0°, 30°, 60°, and 90°.

RESULTS

After we sectioned the ALL (ACL-/ALL-), the mean IR at 0°, 30°, 60°, and 90° of knee flexion were significantly increased, compared to the intact knee (p=<0.001, <0.001, <0.001, and 0.002) and ACL- (p=<0.001, <0.001, <0.001, and 0.002). The additional transection of the ALC (ACL-/ALL-/ALC-) significantly increased IR laxity from the ACL-/ALL- at 30°, 60°, and 90° (p=0.005, 0.003, and 0.047). For anterior laxity, ACL-/ALL- resulted in significantly increased anterior laxity from the ACL- at 30° and 60° (p=0.003 and 0.019), and ACL-/ALL-/ALC- significantly increased anterior laxity even from the ACL-/ALL- at 30° and 60° (p=0.007 and 0.011). For varus laxity, ACL-/ALL- resulted in significantly increased varus laxity from both the intact knee and ACL- at 60° (p=0.004 and 0.007) and 90° (p=<0.001 and<0.001). ACL-/ALL-/ALC- resulted in significantly increased varus from ACL-/ALL- at 60° and 90° (p=<0.001 and 0.003).

CONCLUSION

The anterolateral ligament and anterolateral capsule injuries in ACL-injured knees even with ITB preserved had a synergistic effect on knee laxity in the aspects of internal rotation, anterior translation, and varus angulation.

LEVEL OF EVIDENCE

II, Controlled laboratory study.

Intravenous Ferric Carboxymaltose Improves Response to Postoperative Anemia Following Total Knee Arthroplasty: A Prospective Randomized Controlled Trial in Asian Cohort

Background: Ferric carboxymaltose (FCM) is an intravenous (IV) high-dose iron that is effective in the treatment of iron deficiency anemia. This study was performed to determine whether postoperative FCM infusion is effective at improving hemoglobin (Hb) responders, Hb and iron profiles, and the patient’s quality of life (QOL). Methods: A total of 110 patients with postoperative anemia, defined by a Hb < 10 g/dL within 3 days of unilateral primary TKA, between June 2018 and February 2020 were randomized into either the FCM or Control group. On postoperative day 3, the FCM group (55 patients) received IV FCM while the Control group (55 patients) did not. The Hb responders (Hb increase ≥ 2 g/dL compared to baseline), Hb level, iron profiles (ferritin, total iron-binding capacity (TIBC), transferrin saturation (TSAT)), and EQ-5D scores were compared at weeks 2, 4, and 8. Results: The FCM group demonstrated a significantly greater number of Hb responders (p < 0.001) and a higher Hb level (p = 0.008) at 2 weeks postoperative than did the Control group. The FCM group recovered its preoperative Hb level between 4 and 8 weeks. In contrast, the Control group did not recover its preoperative level until 8 weeks. The FCM infusion group also had higher serum ferritin, iron and TSAT, and lower TIBC levels than those of the Control group between 2 and 8 weeks (all p < 0.001). However, there was no significant difference in the postoperative transfusion rate (p = 0.741) or EQ-5D score between the two groups (all p > 0.05). Discussion: In postoperative anemia following TKA, IV FCM increases the Hb response and improves Hb and iron metabolism variables, however, it does not affect the transfusion rate or QOL.

Risk factors and preventive strategy for excessive coronal inclination of tibial plateau following medial opening-wedge high tibial osteotomy

PURPOSE

To investigate risk factors and suggest preventive strategy for excessive coronal inclination of tibial plateau following medial opening-wedge high tibial osteotomy (MOWHTO).

METHODS

A total of 133 consecutive patients who underwent MOWHTO were retrospectively enrolled. Patients were divided into two groups based on postoperative medial proximal tibial angle (post-MPTA) of 95°: control group (n = 111, 83.5%) with post-MPTA less than 95° and excessive MPTA group (n = 22, 16.5%) with post-MPTA 95° or more. Demographics, radiographic parameters [mechanical lateral distal femoral angle (mLDFA), MPTA, posterior tibial slope, joint line obliquity (JLO), hip-knee-ankle angle, joint line convergence angle (JLCA), weight bearing line ratio, and correction angle], and clinical outcomes of patients were compared. Multiple logistic regression analysis was performed to determine risk factors for post-MPTA 95° or more.

RESULTS

Multiple logistic regression analysis showed that preoperative JLO ≥ 3° [odds ratio (OR) 6.940, 95% confidence interval (CI) 2.373-20.296, p < 0.001] and preoperative JLCA ≥ 5° (OR 5.723, 95% CI 1.833-17.865, p = 0.008) were statistically significant risk factors for post-MPTA ≥ 95°. Incidences of excessive MPTA following MOWHTO in patients with none, one, and two risk factors preoperatively were 3.7%, 26.7%, and 77.8%, respectively.

CONCLUSION

Preoperative JLO ≥ 3° and JLCA ≥ 5° were two significant risk factors for excessive MPTA following MOWHTO. Thus, surgeon should consider other types of osteotomy if these two risk factors are present together preoperatively in MOWHTO candidates.

LEVEL OF EVIDENCE

Level III.

Influence of increased pain sensitivity on patient-reported outcomes following total knee arthroplasty

PURPOSE

The purpose of this study was to discover whether increased pain sensitivity was associated with postoperative pain and patient-reported outcome measures (PROMs) after total knee arthroplasty (TKA).

METHODS

Pain sensitivity was evaluated preoperatively using a pain sensitivity questionnaire (PSQ). Resting, walking, nighttime, and average pain visual analog scale (VAS) were measured before surgery and 6 weeks, 3 months, 6 months, and 1 year after surgery. PROMs were also evaluated based on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and patient satisfaction. The association between pain VAS average score, WOMAC total score, and PSQ score (minor, moderate, and total score) was assessed at each stage.

RESULTS

There were 59 patients with a high PSQ score (≥ 5.2) and 53 with a low PSQ score (< 5.2). Up to 1 year postoperatively, the group with high PSQ scores had higher resting, walking, nighttime, and average pain VAS scores than the group with low scores (all p < 0.05). Worse preoperative WOMAC pain, function, and total scores continued until 1 year after surgery in the high-scoring PSQ group (all p < 0.05). The group with low PSQ scores was more satisfied with surgery than the group with high scores (p = 0.027). There was a positive correlation between preoperative PSQ score and pain VAS average score at all time points (all p < 0.05). A relationship between PSQ score and WOMAC total score was also observed (all p < 0.05).

CONCLUSION

Increased pain sensitivity is a factor related to higher postoperative pain levels and inferior PROMs in patients undergoing primary TKA.

LEVEL OF EVIDENCE

Case-controlled study, III.

Porcine-Derived Collagen-Augmented Chondrogenesis Technique for Treating Knee Cartilage Defects

Articular cartilage is virtually incapable of self-healing in the event of a defect. Microfracture is the most frequently used bone marrow stimulation technique¹, but there is the limitation of unpredictable quality of the cartilage repair following bone marrow stimulation². To resolve the shortcomings of the microfracture technique, various reinforcing technologies have been developed, including the porcine-derived collagen-augmented chondrogenesis technique (C-ACT)³. The collagen gel utilized in that procedure is a product called CartiFill (Sewon Cellontech), made from highly purified pig-derived type-I collagen. It has been modified into an atelocollagen, by removing telopeptides, to virtually eliminate the risk of rejection. The collagen matrix provides not only a 3-dimensional structure for cartilage differentiation, but also mechanical support^3,4.

Description

Porcine-derived C-ACT is initiated by creating a mixture of atelocollagen, thrombin, and fibrinogen. First, thrombin is mixed with atelocollagen and placed in one arm of an assembled Y-shaped syringe, and fibrinogen is placed in the other arm. The articular cartilage defect site is confirmed in a routine arthroscopic procedure. The articular margin is debrided, and the calcified lesion is cleanly removed. Then, microfractures are created. After creating a more extended incision at the anteromedial portal, the microfracture site is prepared by removing moisture. The prepared atelocollagen mixture is applied to the defect site as a single layer, although a second layer can be formed 1 to 2 minutes later. After 5 minutes, the stability is verified by range of motion of the knee.Indications for this procedure include (1) cartilage defects in the knee, including knee osteoarthritis and knee traumatic arthritis; (2) knee osteoarthritis with a Kellgren-Lawrence grade of 3 or less; (3) hip-knee-ankle malalignment of <5° or a deformity that is able to be surgically corrected; and (4) knee stability, or instability that is able to be surgically corrected.Contraindications for this procedure include (1) patient or family history of autoimmune disease, (2) history of anaphylactic reaction, (3) history of hypersensitivity to an implant, (4) history of allergy to porcine or bovine protein, and (5) inflammatory arthritis such as rheumatoid and gouty arthritis.C-ACT is a procedure for cartilage repair, and the effects of this procedure can be limited in cases with a deep subchondral bone defect; however, there is no limit to the size of the cartilage defect in terms of patient selection for C-ACT.

Alternatives

There are several alternatives to C-ACT, ranging from the simple microfracture technique to autologous chondrocyte implantation⁵, matrix-induced autologous chondrocyte implantation⁶, autologous matrix-induced chondrogenesis⁷, osteochondral autograft transplantation⁸, and stem cell therapy. There are various ways to recover from an articular cartilage defect, but C-ACT does not require a 2-stage technique, as is necessary with both autologous chondrocyte implantation procedures. Therefore, C-ACT has the advantages of ease of operation and being a single-stage procedure^3,9.

Rationale

C-ACT can be classified as an upgraded version of microfracture, which is the most common treatment method for articular cartilage defects. With the microfracture technique, repaired cartilage is limited to fibrous cartilage and does not include hyaline cartilage^3,4. However, a recent study reported that C-ACT exhibited a superior quality of repaired cartilage compared with microfracture^3,4.

Expected Outcomes

Previous studies have reported favorable results with the use of C-ACT^3,4. Kim et al.⁴ compared atelocollagen augmentation with microfracture alone in patients undergoing medial opening wedge high tibial osteotomy for the treatment of medial compartment osteoarthritis. Although there was no clinical difference between the 2 groups, the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score and the International Cartilage Repair Society II score were superior in the atelocollagen augmentation group. In addition, the microfracture group formed fibrous-like cartilage compared with the hyaline-like cartilage created in the atelocollagen augmentation group. A recent multicenter randomized study compared the use of C-ACT and microfracture and found that C-ACT exhibited significantly better results in several MOCART subscores and quantitative T2 mapping, indicating a histologically superior form of repaired cartilage compared with microfracture³. According to recent research, microfracture is superior to autologous chondrocyte implantation in terms of cost-effectiveness¹⁰. Similar results appear to be applicable to C-ACT. C-ACT requires an additional $1,300 for material costs; however, C-ACT showed better cartilage regeneration on magnetic resonance imagining and histology^3,4, and higher rate of patients meeting the 20%-improvement rate in visual analogue scale pain scores at 24 months postoperatively compared with microfracture³. Long-term studies will be needed to assess whether histological superiority of C-ACT is reflected in meaningful improvements to clinical outcomes.

Important Tips

Debride all of the damaged cartilage to subchondral bone and remove the calcified layer without interfering with tissue repairTake special care when creating the atelocollagen mixture to ensure that it is accurately manufacturedDry the defect site with use of suction or gauze to aid in atelocollagen adhesion when applying atelocollagen.

2-Octyl Cyanoacrylate Topical Adhesive as an Alternative to Subcuticular Suture for Skin Closure After Total Knee Arthroplasty: A Randomized Controlled Trial in the Same Patient

BACKGROUND

The 2-octyl cyanoacrylate topical adhesive with flexible self-adhesive polyester mesh (Dermabond Prineo) is becoming widely used in many surgical fields. However, no prior studies have tested the efficacy and safety of this topical adhesive compared with subcuticular suture in the same patient. The purpose of this study was to compare the efficacy and safety between Dermabond Prineo and subcuticular suture for skin closure in patients undergoing same-day bilateral total knee arthroplasties (TKAs).

MATERIALS AND METHODS

A prospective, double-blind randomized controlled trial was performed in 51 patients scheduled to undergo same-day bilateral TKAs. One knee was randomly assigned to the Dermabond Prineo and the other knee was allocated to the subcuticular suture. As primary outcomes, Vancouver scar scale was evaluated at 6 months and Patient and Observer Scar Assessment Scale was evaluated at 2 weeks, 6 weeks, 3 months, and 6 months. Secondary outcomes included cosmesis efficacy (Hollander wound evaluation scale [HWES] and cosmesis visual analog scale [VAS]), time and pain efficiency (skin suture time, stitch out time, and stitch out pain VAS), and safety (wound complications during the 6-month follow-up period). The primary and secondary outcome measures were compared between groups.

RESULTS

There were no significant differences in Vancouver scar scale and Patient and Observer Scar Assessment Scale at 6 months. Although there were no significant differences in HWES at 2 weeks, the Dermabond Prineo group showed better step-off border item of HWES. There was also no difference in cosmesis VAS at 6 months. The Dermabond Prineo group showed superior results in terms of time (suture time: Dermabond Prineo = 191 second (sec) ± 60.1 sec, subcuticular suture = 356.8 sec ± 92.3 sec; stitch out time: Dermabond Prineo = 4 sec ± 1.3 sec, subcuticular suture = 26.6 sec ± 4.2 sec, all P < .001) without significant differences in pain scale (P = .823) or wound complications (all P > .05).

CONCLUSION

Comparing cosmetic efficacy, time efficiency, and safety, Dermabond Prineo provided quicker wound closure, shorter stitch out time, and better wound margin coaptation in the early postoperative period but similar cosmetic efficacy compared with subcuticular suture. Based on our study, Dermabond Prineo is a useful alternative to subcuticular suture in patients undergoing TKA.

LEVEL OF EVIDENCE

Therapeutic level 1.

Minimal Clinically Important Differences for Patient-Reported Outcomes After TKA Depend on Central Sensitization

BACKGROUND

To our knowledge, it is still unknown if central sensitization (CS) influences the magnitude of the minimal clinically important difference (MCID) for patient-reported outcome measures after total knee arthroplasty (TKA). The purpose of this study was to determine the influence of CS on the MCID for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score in patients who underwent TKA for knee osteoarthritis.

METHODS

A total of 422 patients who underwent unilateral TKA and completed a 2-year follow-up were enrolled in this study. CS was measured using the Central Sensitization Inventory (CSI). The WOMAC score was used to evaluate preoperative and postoperative patient-reported outcomes. The measurement of the MCID was performed separately for patients with and without CS using both the anchor-based method and the distribution method. The change difference method defined the MCID as the difference in preoperative-to-postoperative change between the minimal-improvement group and the no-change group. In addition, the MCID was calculated using receiver operating characteristic (ROC) curve analysis. The percentage of MCID achievement in each group was also compared.

RESULTS

According to the change difference method, the MCID for the WOMAC total score was 23.4 points for patients with CS and 14.7 points for patients without CS. The MCID using the ROC cutoff value for the WOMAC total score was 29.5 points for the patients with CS and 26.5 points for the patients without CS. MCID achievement rates in WOMAC pain, function, and total scores were all found to be significantly higher in the patients without CS through the change difference method and the ROC method (all p < 0.05).

CONCLUSIONS

The MCID for the WOMAC score of patients with CS after TKA was greater than that for patients without CS. Furthermore, by applying the calculated MCID to the group to which the patients belonged (with or without CS), we determined that patients with CS showed a lower MCID achievement rate than patients without CS.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Efficacy of duloxetine compared with opioid for postoperative pain control following total knee arthroplasty

Background

The purpose of this study was to assess the efficacy of duloxetine as an alternative to opioid treatment for postoperative pain management following total knee arthroplasty (TKA).

Methods

Among 944 patients, 290 (30.7%) of patients received opioid or duloxetine for pain control for 6 weeks when the pain Visual Analogue Scale (VAS) score was greater than 4 out of 10 at the time of discharge. 121 patients in the Opioid group and 118 in the Duloxetine group were followed up for more than one year. Preoperative and postoperative patient reported outcome measures (pain VAS score, Western Ontario and McMaster Universities OA Index (WOMAC) score were compared. The rate of further drug prescription (opioid or duloxetine) after 6 weeks of first prescription, 30-day readmission rate, and side effects were also investigated.

Results

There was no significant difference in pain VAS score, WOMAC Pain and Function score, at each time point between before and after surgery (all p>0.05). Fifteen (9.8%) patients in the opioid group and six (4.4%) patients in the duloxetine group were prescribed additional medication after first 6 weeks, showing no significant (p>0.05) difference in proportion. The 30-day readmission rate and the incidence of side effects were also similar (all p>0.05). There was no difference in the incidence of side effects between the two groups (p>0.05).

Conclusion

Duloxetine and opioid did not show any difference in pain control, function, and side effects for up to one year after TKA. Although large-scale randomized controlled trials are still required to further confirm the side effects of duloxetine, it can be considered as an alternative to opioid for postoperative pain control following TKA.

The Minimal Clinically Important Difference (MCID) for the WOMAC and Factors Related to Achievement of the MCID After Medial Opening Wedge High Tibial Osteotomy for Knee Osteoarthritis

BACKGROUND

Many approaches have been used to determine the minimal clinically important difference (MCID) in patients undergoing total knee arthroplasty, but the MCID for outcome measures after medial opening wedge high tibial osteotomy (MOWHTO) for the treatment of medial compartment knee osteoarthritis (OA) has not been reported.

PURPOSE

To define the MCID for the Western Ontario and McMaster Universities Arthritis Index (WOMAC) after MOWHTO and to identify risk factors for not achieving the MCID.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Among patients with medial compartment knee OA who underwent MOWHTO, 174 patients who were followed for 2 years were included in the study. The MCID and substantial clinical benefit (SCB) for the WOMAC were determined using the anchor-based method with a 15-item questionnaire. Preoperative OA severity was measured by the Kellgren-Lawrence (K-L) grading system, and the acceptable range of the postoperative weightbearing line ratio was 50% to 70%. Patients were divided into 2 groups based on whether the MCID and SCB were achieved, and then factors related to failure to achieve the MCID and SCB were analyzed using multivariate logistic regression analysis.

RESULTS

The MCID for the WOMAC was 4.2 points for the pain subscale, 1.9 points for the stiffness subscale, 10.1 points for the function subscale, and 16.1 points for the total. Additionally, the SCB for the WOMAC was 6.4 for pain, 2.6 for stiffness, 16.4 for function, and 25.3 for the total. Overall, 116 (66.7%), 99 (56.9%), 127 (73.0%), and 128 (73.6%) patients achieved the MCID for the WOMAC pain, stiffness, function, and total, respectively, after MOWHTO. The odds of not achieving the MCID for the WOMAC total were 1.09 times greater (95% CI, 1.05-1.13; P < .001) in patients with a low preoperative WOMAC total score (cutoff values: 10.5 for pain, 3.5 for stiffness, 34.5 for function, and 51.0 for the total), 11.77 times greater (95% CI, 3.68-37.70; P < .001) in patients with K-L grade 4 OA compared with K-L grades 2 or 3 OA, and 8.39 times greater (95% CI, 2.98-23.63; P < .001) in patients with undercorrection or overcorrection. A low preoperative WOMAC score, K-L grade 4 OA, and undercorrection or overcorrection were also associated with not achieving the SCB for the WOMAC total (all P < .05).

CONCLUSION

Patients treated with a MOWHTO require a 16.1-point improvement in the WOMAC total score to achieve a MCID from the procedure. Low preoperative WOMAC scores, severe OA, and undercorrection or overcorrection were related to failure to achieve the MCID.

Double-Bundle Anterior Cruciate Ligament Reconstruction With Lateral Extra-Articular Tenodesis Is Effective in Restoring Knee Stability in a Chronic, Complex Anterior Cruciate Ligament-Injured Knee Model: A Cadaveric Biomechanical Study

PURPOSE

To compare knee stability after intra-articular isolated double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) and single-bundle (SB) and DB ACLR combined with lateral extra-articular tenodesis (LET) in a chronic, complex anterior cruciate ligament (ACL)-injured knee model.

METHODS

In 10 fresh-frozen cadaveric knees, we measured knee laxity in the following order: (1) intact knee; (2) ACL-sectioned knee; (3) complex ACL-injured knee model with additional sectioning of the anterolateral complex and the posterior horns of the medial and lateral menisci; (4) SB ACLR plus LET; (5) DB ACLR; and (6) DB ACLR plus LET.

RESULTS

In comparison with the intact knee, significantly increased internal rotation (IR) laxity persisted at 60° and 90° after DB ACLR (P = .002 and P = .003, respectively). SB ACLR plus LET and DB ACLR plus LET resulted in significant reductions in IR laxity at 90° (P = .003 and P = .037, respectively), representing overconstraint in IR. SB ACLR plus LET resulted in persistently increased external rotation (ER) laxity at 30°, 60°, and 90° (P = .001, P < .001, and P < .001, respectively). The DB ACLR condition persistently showed significant increases in anterior tibial translation laxity at 60° and 90° (P = .037 and P = .024, respectively). A greater increase in ER laxity was seen after SB ACLR plus LET versus DB ACLR plus LET at 30°, 60°, and 90° (P < .001, P < .001, and P < .001, respectively).

CONCLUSIONS

DB ACLR plus LET restored intact knee stability in IR, ER, and anterior tibial translation laxity at 0°, 30°, 60°, and 90° of knee flexion except for overconstraint in IR at 90° in a chronic, complex ACL-injured knee model.

CLINICAL RELEVANCE

This cadaveric study provides some biomechanical evidence to support performing DB ACLR combined with LET to restore knee stability after a complex, chronic knee injury involving an ACL tear combined with anterolateral complex injury and irreparable tears of the posterior horns of the medial and lateral menisci.

Efficacy and safety of celecoxib combined with JOINS in the treatment of degenerative knee osteoarthritis: study protocol of a randomized controlled trial

Background

The aim of this study will be to investigate the therapeutic effect and safety of non-steroidal anti-inflammatory drugs (NSAIDs) along with symptomatic slow-acting drugs for the treatment of osteoarthritis (SYSADOA), JOINS tablets, for degenerative knee osteoarthritis (OA) treatment and to determine the analgesic and anti-inflammatory effects of the combination therapy. In addition, we will investigate whether JOINS treatment alone after NSAID and JOINS combination treatment is effective in relieving and maintaining knee OA symptoms.

Methods

This study will be a prospective, randomized, double-blind endpoint study design. All patients will be randomly assigned to either intervention (celecoxib+JOINS) or control (celecoxib+placebo) groups. In Part 1, the intervention group will be administered celecoxib once a day and JOINS three times a day for a total of 12 weeks. In the control group, celecoxib will be administered once a day and JOINS placebo three times a day for a total of 12 weeks. In Part 2, JOINS alone and JOINS placebo alone will be administered for an additional 24 weeks in both groups, respectively. The primary endpoint will be the amount of change during the 12 weeks as assessed using the Western Ontario and McMaster Universities Osteoarthritis Index total score compared with baseline. The secondary endpoint will be the amount of change at 1, 4, 12, 24, and 36 weeks from the baseline for pain visual analog scale, Brief Pain Inventory, Short Form Health Survey-36 and biomarkers.

Results

The trial was registered with Clinical-Trials.gov (NCT04718649). The clinical trial was also registered on Clinical Research Information Service (CRIS) with the trial registration number KCT0005742.

Conclusions

The combination treatment of the most commonly used SYSADOA drug, JOINS, and selective COX-2 inhibitor celecoxib as the representative NSAID for knee OA treatment, can be compared with celecoxib alone treatment to determine the safety or therapeutic effect.

Alignment adjustment using the Valgus stress technique can increase the surgical accuracy of novice surgeons during medial opening-wedge high Tibial osteotomy

Background

The purpose of this study was to compare the degree of accuracy of coronal alignment correction with use of the “alignment adjustment under valgus stress technique” between expert and novice surgeons during medial opening-wedge high tibial osteotomy (MOWHTO).

Methods

Forty-eight patients who underwent MOWHTO performed by an expert surgeon (expert group) and 29 by a novice surgeon (novice group) were enrolled in analysis. During surgery, lower-extremity alignment was corrected using the “alignment adjustment under valgus stress technique”. Normocorrection was defined as a weight-bearing line ratio between 55 and 70% and the correction accuracy was compared between expert and novice groups using the ratio of normocorrection to outliers. The clinical outcomes were also compared using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at 1 year after surgery.

Results

The undercorrection rate was 14.6% in the expert group and 13.8% in the novice group, while the overcorrection rate was 2.1% in the expert group and 3.4% in the novice group. In the ratio of normocorrection to outliers, no difference was found between the two groups at the one-year follow-up visit (83.3% in the expert group vs. 82.8% in the novice group; p > 0.05). Also, no significant differences were seen in WOMAC subscores immediately preoperatively and at 1 year after surgery (all p > 0.05).

Conclusion

Adhering to the “alignment adjustment under valgus stress technique” protocol enabled novice surgeons to achieve similar surgical accuracy as that of an expert surgeon in coronal alignment during MOWHTO.

Level of evidence

Level III.

Total knee arthroplasty in femoral bowing: does patient specific instrumentation have something to add? A randomized controlled trial

BACKGROUND

Patient-specific instrumentation (PSI) proponents have suggested the benefits of improved component alignment and reduced outliers. In this randomized controlled trial, we attempted to assess the advantage of using PSI over conventional intermedullary (IM) guides for primary total knee arthroplasty (TKA) with bilateral severe femoral bowing (> 5°). A parallel trial design was used with 1:1 allocation. We hypothesize that PSI would support more accurate alignment of components and the lower-limb axis during TKA with severe femoral bowing in comparison with conventional IM guides.

METHODS

Among 336 patients undergoing bilateral TKAs due to knee osteoarthritis, 29 patients with bilateral lateral femoral bowing of more than 5° were included in this study. Every patient was assigned randomly to PSI on one side and to conventional instrumentation lateralization of the entry point of the femoral IM guide was applied on the other with a goal of neutral mechanical alignment. The assessment of coronal alignment was completed by measuring the hip-knee-ankle (HKA) angle on preoperative and postoperative long film standing radiographs. Coronal and sagittal orientations of femoral and tibial components were assessed on weight-bearing radiographs. The rotational alignment of the femoral component was evaluated using computed tomography.

RESULTS

The postoperative mean ± standard deviation (SD) HKA angle was varus 4.0° (± 2.7°) for conventional technique and varus 4.1° (± 3.1°) for PSI, with no differences between the two groups (p = 0.459). The component orientation showed no significant differences except with respect to the sagittal alignment of the femoral component (p = 0.001), with a PSI mean ± SD flexion of 5.8° (± 3.7°) and a conventional method mean ± SD flexion of 3.2° (± 2.5°), due to the intentional 3° flexion incorporated in the sagittal plane to prevent femoral notching in PSI planning. Computed tomography assessment for rotational alignment of the femoral components showed no difference between the two groups concerning the transepicondylar axis (p = 0.485) with a PSI mean ± SD external rotation of 1.5° (± 1.3°) and conventional mean ± SD external rotation of 1.5° (± 1.6°).

CONCLUSION

PSI showed no advantage over lateralization of the femoral entry for IM guidance.

LEVEL OF EVIDENCE

1 TRIAL REGISTRATION: Registered on US national library of medicine ClinicalTrials.gov ( NCT02993016 ) on December 12^th 2016.

Medial Meniscal Ramp Lesion Repair Through Anterior Portals Using a Medial Collateral Ligament Pie-Crusting Technique

Ramp injury, that is, injury to the peripheral attachment of the posterior horn of the medial meniscus, often requires additional surgery during anterior cruciate ligament (ACL) reconstruction. Diagnosis and treatment of ramp lesions are important because unrepaired ramp lesions could cause risk to the reconstructed ACL because of anteroposterior and external rotation laxity, whereas acute rupture or chronic deficiency of the ACL could also cause ramp lesions because of instability. Ramp lesions are difficult to diagnose and treat from the anterior compartment during arthroscopy. Typically, this repair requires technically demanding skills and is performed from the posterior portal using a suture hook under visualization with the arthroscope through the intercondylar notch. Inexperienced surgeons often struggle with using the posterior portal and the suture hook. Our all-inside repair technique using the FasT-Fix system (Smith & Nephew, Andover, MA) under direct visualization from the anterior compartment accompanied by a medial collateral ligament pie-crusting technique facilitates repair of ramp lesions without causing medial instability.

Comparison of Joint Perception Between Posterior-Stabilized and Ultracongruent Total Knee Arthroplasty in the Same Patient

BACKGROUND

Posterior-stabilized and ultracongruent designs are 2 common examples of posterior cruciate ligament-substituting total knee arthroplasty (TKA) prostheses. There is a lack of evidence regarding joint perception differences between ultracongruent and posterior-stabilized TKA. The purpose of this study was to compare the postoperative knee stability, function, and joint perception between ultracongruent and posterior-stabilized TKA in the same patients in order to determine whether there was a difference based on design.

METHODS

This prospective, randomized controlled trial included 50 patients who underwent same-day bilateral TKA utilizing Persona (Zimmer Biomet) posterior-stabilized implants in 1 knee (posterior-stabilized group) and ultracongruent implants in the other knee (ultracongruent group). At 2 years postoperatively, patients were evaluated for knee stability, function, and joint perception. Postoperative static knee anteroposterior stability and femoral rollback were compared. Knee function was evaluated with use of the Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Joint perception was compared by evaluating noise generation, side preference, satisfaction, and the Forgotten Joint Score.

RESULTS

The ultracongruent group had more knee anteroposterior laxity (4.5 mm compared with 1.8 mm in the posterior-stabilized group; p < 0.001) and less femoral rollback (4.2 mm compared with 9.0 mm in the posterior-stabilized group; p < 0.001). Knee Society Score and WOMAC scores were not significantly different between groups (all p > 0.05). Although the ultracongruent group showed less noise generation than the posterior-stabilized group (18% compared with 38%, respectively; p = 0.026), there were no differences in side preference, satisfaction, or Forgotten Joint Score (all p > 0.05).

CONCLUSIONS

Both groups had similar joint perception 2 years postoperatively, with obvious differences in noise generation and more sagittal laxity with less femoral rollback in the ultracongruent group.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Cross-cultural adaptation and validation of the Korean version of the Central Sensitization Inventory in patients undergoing total knee arthroplasty for knee osteoarthritis

The purpose of this study was to establish a Korean version of the Central Sensitization Inventory (CSI-K) for Korean-speaking patients facing total knee arthroplasty (TKA) for knee osteoarthritis (OA) and to investigate the psychometric characteristics of the CSI-K. We recruited a total of 269 patients with knee OA who were scheduled to undergo TKA for the study. CSI-K and pain-related outcomes, including the pain visual analog scale (VAS) and the Western Ontario and McMaster Universities OA Index (WOMAC) pain sub-scores, were measured. Since central sensitization (CS) is closely related to the quality of life (QOL) and limited functionality as well as pain, the patient's function was measured using the WOMAC function sub-scores, and QOL was measured using the EuroQol five-dimension test (EQ-5D). Reliability and validity were evaluated. Exploratory factor analysis (EFA) was conducted to begin the data reduction to validate the existing questionnaire translation. The internal consistency was excellent, with a Cronbach's alpha of 0.941. The test-retest reliability was acceptable-to-excellent with an ICC of 0.888. As expected, the CSI scores correlated strongly with the WOMAC pain scores (r = 0.524, p < 0.001) and moderately with the pain VAS (r = 0.496, p < 0.001), the WOMAC function (r = 0.408, p < 0.001), and the EQ-5D scores (r = 0.437, p < 0.001). EFA resulted in a six-factor model. The findings demonstrate that the CSI was successfully trans-culturally adapted into a simplified Korean version (CSI-K) that was reliable and valid for Korean-speaking patients who awaiting TKA for knee OA.

Patient Expectations and Satisfaction After Medial Opening Wedge High Tibial Osteotomy

BACKGROUND

The objective of this study is to assess preoperative patient expectations of medial opening wedge high tibial osteotomy (MOWHTO) and related postoperative fulfillment, to increase understanding of associated factors of postoperative satisfaction.

METHODS

One hundred fifteen patients who underwent MOWHTO were enrolled. Patients' expectations were measured using the Hospital for Special Surgery-Knee Replacement Expectations Survey. Fulfillment of expectations and satisfaction was evaluated using the Hospital for Special Surgery Knee Replacement Fulfillment of Expectations Survey and a 5-point Likert scale at 2 years, postoperatively. The discrepancies between preoperative expectation and postoperative fulfillment score were also assessed. Preoperative and postoperative patient-reported outcomes were evaluated using Western Ontario and McMaster Universities Arthritis Index (WOMAC) score. Univariate and multivariate analyses were performed to model predictions for satisfaction.

RESULTS

The most expected items were "pain relief," "walking ability," and "perform daily activities." The top 3 items with the biggest discrepancies between expectation and fulfillment scores were "kneeling," "squatting," and "pain relief." Ninety patients (78.3%) were satisfied and 25 (21.7%) were dissatisfied at 2 years postoperative. Multivariate logistic regressions showed that patient expectations did not affect satisfaction. Small discrepancies between expectation and fulfillment scores (odds ratio [OR] 105.304, 95% confidence interval 20.974-528.714, P < .001), high postoperative fulfillment scores (OR 1.198, 95% CI 1.110-1.293, P < .001), and low postoperative Western Ontario and McMaster Universities Arthritis Index total scores (OR 0.932, 95% CI 0.894-0.971, P < .001) were significantly associated with patient satisfaction.

CONCLUSION

The small discrepancy between preoperative expectations and postoperative fulfillment of expectations was a major contributor to patients' satisfaction following MOWHTO.

Modified hybrid cementing technique reduces stem tip pain and improves patient's satisfaction after revision total knee arthroplasty

Background

There have been no studies comparing patient-reported outcome measures including end-of-stem tip pain and patient satisfaction based on the use of cementing techniques in revision total knee arthroplasty (TKA). The purpose of this study was to compare end-of-stem tip pain and PROMs with hybrid and modified hybrid cementing techniques in revision TKAs.

Method

Sixty-two cases of revision TKA performed by a single surgeon were divided into two groups based on the cementing technique with a minimum follow-up of 2 years. Two types of cementing technique for femoral and tibial stems were used as follows: (1) a hybrid cementing technique (33 cases), in which cement was applied immediately distal to the modular junction of the stem and the component while the distal stem was press-fitted into the diaphysis without using cement; and (2) a modified hybrid cementing technique (29 cases), in which cement was applied to the tip of femoral and tibial stems. The thigh and shin were assessed for the end-of-stem tip pain. Patient satisfaction was evaluated based on the satisfaction items of New Knee Society Score.

Results

Modified hybrid cementing significantly lowered the percentage of patients manifesting shin pain (3.4% vs. 24.2%, p = 0.029). Patients treated with the modified hybrid cementing technique showed a higher satisfaction rate (p = 0.003). Multivariate logistic regression analysis showed an increase in the odds of satisfaction 32.686-fold (p = 0.004) in patients without pain at the end-of-stem tip in the shin and 9.261-fold (p = 0.027) in patients treated with the modified hybrid cementing technique.

Conclusion

The modified hybrid cementing technique for fixation of long-stem in revision TKAs reduced the end-of-stem tip pain in the shin, leading to significantly higher satisfaction compared with the hybrid cementing technique after revision TKA.

Level of evidence

Level III

Knee laxity in anterolateral complex injuries versus medial meniscus posterior horn injuries in anterior cruciate ligament injured knees: A cadaveric study

INTRODUCTION

There is considerable debate regarding the function of anterolateral knee structures, including the anterolateral ligament (ALL) and anterolateral capsule, as knee stabilizers in anterior cruciate ligament (ACL) injured knees. Medial meniscus posterior horn (MMPH) injuries have also been associated with increased knee laxity in ACL injured knees. The purpose of this cadaveric biomechanical study was to compare the effects of the anterolateral complex (ALC) injury and meniscectomy of MMPH on knee laxity in ACL injured knees.

HYPOTHESIS

ALC injury would have a greater effect on internal rotational laxity in ACL-injured knee than meniscectomy of MMPH.

MATERIAL AND METHODS

Matched-pair 10 fresh-frozen cadaveric knees underwent biomechanical evaluation of knee laxity. After testing the intact knee and ACL sectioned knee (ACL-) in matched-pair 10 fresh-frozen cadaveric knees, two groups were established: an ALC sectioning (ACL-/ALC-) group (n=5) and a MMPH meniscectomy (ACL-/MMPH-) group (n=5). Knee laxity was measured in terms of internal-external rotation, anterior-posterior translation, and varus-valgus angulation for each condition at knee flexion angles of 0°, 30°, 60° and 90°.

RESULTS

After the additional sectioning of the ALC (ACL-/ALC-), the mean internal rotation at 0°, 30°, 60° and 90° of knee flexion showed the greater internal rotation laxity compared than intact knee (p=0.020, 0.011, 0.005 and<0.001). It also significantly increased anterior translation from ACL- at 30° and 60° (p=0.011 and 0.005). In contrast, additional meniscectomy of the MMPH (ACL-/MMPH-) significantly increased external rotation laxity compared to intact knee (p=0.021, 0.018 and 0.024) and ACL- (p=0.037, 0.011 and 0.025) at 30°, 60° and 90°. ACL-/MMPH- also resulted in significantly increased anterior translation from ACL- at 30°, 60° and 90° (p=0.004, 0.008 and 0.002).

DISCUSSION

In conclusion, the anterolateral complex, which include the ALL and anterolateral capsule, may play an important role in stabilizing the knee against internal rotation and anterior translation, while the MMPH may contribute to resisting external rotation and anterior translation stability in ACL-injured knee.

LEVEL OF EVIDENCE

II, controlled laboratory study.

Confirmation of Femoral Button Deployment Under Direct Visualization During ACL Reconstruction Is Not Beneficial

The purpose of this study was to determine whether direct visualization of adjustable-loop cortical suspensory button deployment onto the lateral femur increases the cortical contact rate of the button, thereby improving clinical outcomes after anterior cruciate ligament (ACL) reconstruction. Sixty-five single-bundle anteromedial portal ACL reconstructions using an adjustable-loop button were retrospectively divided into 2 groups according to use of the blind pulling technique (control group; 32 patients) or the direct visualization technique (visualization group; 33 patients) when confirming deployment of the button. Cortical contact rate of the button on immediate and 2-year postoperative radiographs, knee stability measured using a KT-1000 arthrometer, and functional scores (Lysholm score and International Knee Documentation Committee score) at 2 years postoperative were compared between the groups. There was no significant difference in femoral cortical contact rate between the groups immediately (56% control group vs 55% visualization group; P=1.000) and at 2 years postoperative (78% control group vs 82% visualization group; P=.764). At 2 years postoperative, there was no difference between the groups regarding knee stability (1.3±0.9 mm vs 1.5±0.8 mm, respectively; P=.404), Lysholm score (P=.436), and International Knee Documentation Committee score (P=.507). Confirmation of adjustable-loop button deployment under direct visualization during anteromedial portal ACL reconstruction neither increased cortical contact rate nor improved clinical outcomes. [Orthopedics. 2020;43(5);270-276.].

Preoperative Medial Meniscal Extrusion Is Associated With Patient-Reported Outcomes After Medial Opening Wedge High Tibial Osteotomy

BACKGROUND

Although the medial compartment continues to sustain some loading after medial opening wedge high tibial osteotomy (MOWHTO) in varus-deformed knees, no studies have examined the relationship between medial meniscal extrusion (MME) and patient-reported outcome measures after MOWHTO.

PURPOSE

To examine whether compartmental baseline MME was associated with patient-reported outcome measures after MOWHTO.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This retrospective study was composed of 149 MOWHTOs in 147 patients with clinical and radiological assessments. Patients were grouped according to severity of MME in the medial compartment at the time of surgery. MME was categorized into 4 groups according to MOAKS (MRI [magnetic resonance imaging] Osteoarthritis Knee Score) criteria and relative value of MME. We compared preoperative characteristics, including Kellgren-Lawrence (KL) grading scale, meniscal tear pattern, and postoperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) subscores. Associations between extent of MME and WOMAC subscores at postoperative 1 and 2 years were assessed with generalized linear models.

RESULTS

Pattern of meniscal tear (P < .05) and KL grade (P < .05) were associated with MME. Patients with KL grades 3 and 4 at the time of surgery had significantly greater MME than those with KL grade 2 (P < .05). When patients were divided into 4 groups according to MOAKS criteria at the time of surgery, there were significant differences in WOMAC pain scores among groups at 1 and 2 years after the operation (all P < .05). The WOMAC function score also differed among groups at postoperative 1 year (P < .05) but not postoperative 2 years (P > .05). When patients were divided into 4 groups according to relative MME at the time surgery, the WOMAC pain score differed significantly among groups at postoperative 1 and 2 years (all P < .05). Analysis of WOMAC pain score as the dependent variable in multivariate analyses revealed that severity of absolute and relative MME and KL grade were independent predictors of worse WOMAC pain score at postoperative 1 and 2 years (all P < .05).

CONCLUSION

Greater preoperative MME at the time of surgery was associated with inferior patient-reported outcomes, especially pain, in patients with MOWHTO at 1 and 2 years after surgery.

How Does Preoperative Central Sensitization Affect Quality of Life Following Total Knee Arthroplasty?

BACKGROUND

Central sensitization (CS) has been recently identified as a significant risk factor for persistent pain and patient dissatisfaction following total knee arthroplasty (TKA). However, it remains unclear as to whether the preoperative CS persists after the elimination of a nociceptive pain source by TKA, or how CS affects the quality of life after TKA.

METHODS

A total of 222 consecutive patients undergoing primary TKA were enrolled in the study. All patients were preoperatively screened for CS using the Central Sensitization Inventory (CSI) and categorized into either a CS (n = 55; CSI ≥ 40) or non-CS group (n = 167; CSI < 40). CSI, pain visual analog scale (VAS), Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index score, and satisfaction were recorded at postoperative 2 years.

RESULTS

Two years after TKA, preoperative CS remained unchanged; there was no difference between preoperative and postoperative CSI scores, and both preoperative and postoperative CSI severity levels were similar (P > .1). The CS group showed worse pain VAS, KSS, and Western Ontario and McMaster Universities Osteoarthritis Index scores than did the non-CS group (P < .01) and more patients in the CS group were dissatisfied with all activities (P < .01). However, a similar percentage of the CS group achieved the previously documented minimal clinically important difference in pain VAS and KSS, compared with the non-CS group. Multivariate regression analysis revealed that preoperative CSI scores were associated with dissatisfaction at postoperative 2 years.

CONCLUSION

Preoperative CS was persistent at 2 years after TKA. Although CS patients achieved comparable clinical improvement following TKA, CS patients had worse quality of life, functional disability, and dissatisfaction than non-CS patients.

Comparison of implant position and joint awareness between fixed- and mobile-bearing unicompartmental knee arthroplasty: a minimum of five year follow-up study

PURPOSE

To compare the implant position and patient-reported outcomes (PROs) regarding joint awareness using the Forgotten Joint Score (FJS) following between fixed-bearing (FB) and mobile-bearing (MB) unicompartmental knee arthroplasty (UKA) with a minimum of five years' follow-up.

METHODS

One hundred fifteen consecutive UKAs (58 FB UKAs and 57 MB UKAs) performed were retrospectively evaluated. We compared the radiographic parameters including component positions and relationships as well as lower extremity alignment. Post-operative clinical outcomes were assessed using Knee Society Score (KSS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Tegner activity score, and FJS.

RESULTS

The MB UKA group showed more convergent componentry relationship between femoral and tibial components (p < 0.001). The joint line of the MB UKA group was restored significantly better (p < 0.05). In addition, the positioning of femoral and tibial components of the MB UKA group showed less deviation from the weight-bearing line (WBL) (p < 0.05). Although there were no differences in KSS, WOMAC, and Tegner activity scores between the groups, the MB UKA group showed significantly better FJS than did the FB UKA group at five years post-operatively (p < 0.05).

CONCLUSION

The MB UKA group had a more convergent componentry relationship, less deviation from WBL, better joint-line restoration, and reduced joint awareness than did the FB UKA group at five years follow-up.

Isometric Anterolateral Ligament Reconstruction Using the Semitendinosus Tendon With Suspensory Tibial Fixation

The anterolateral ligament (ALL) plays an important role in isolated anterior cruciate ligament reconstruction by providing rotational stability in a combined anterior cruciate ligament and anterolaterally injured knee. Although the ALL has been difficult to characterize anatomically, it originates near the lateral epicondyle of the distal femur and inserts into the proximal tibia between Gerdy's tubercle and the fibula head. Here, we describe an isometric ALL reconstruction using the semitendinosus tendon and an adjustable length loop suspensory tibial fixation. With this technique, it is possible to provide good stability and satisfactory results for patients with rotational instability of the knee.

What Factors Predict Patient Dissatisfaction After Contemporary Medial Opening-Wedge High Tibial Osteotomy?

BACKGROUND

Although current advances in surgical techniques have improved outcomes of the medial opening-wedge high tibial osteotomy (MOWHTO), the factors associated with patient dissatisfaction remain unclear. Thus, the purpose of this study is to identify risk factors for patient dissatisfaction following contemporary MOWHTO.

METHODS

We retrospectively reviewed prospectively collected data on 140 consecutive MOWHTO patients using an anatomical locking plate with a minimum follow-up of 2 years. Patient demographics, pain Visual Analogue Scale, Western Ontario and McMaster Universities Osteoarthritis Index, Kellgren-Lawrence (K-L) grade, activity level, articular cartilage and meniscal status, hip-knee-ankle angle, change in alignment, and postoperative weight-bearing line ratio were recorded. Patients were categorized using the New Knee Society Score into satisfied (satisfaction score ≥20) or dissatisfied (satisfaction score <20) groups. Patient and surgical factors were compared between the groups by the identified predictors. Multiple logistic regression analysis was used to analyze risk factors, including K-L grade IV medial osteoarthritis (OA), preoperative pain Visual Analogue Scale, total Western Ontario and McMaster Universities Osteoarthritis Index score, postoperative hip-knee-ankle angle, change in alignment, and partial meniscectomy.

RESULTS

Of the 140 patients, 24 (17.1%) were dissatisfied with their results. Multiple logistic regression analysis showed that only K-L grade IV medial OA was statistically associated with patient dissatisfaction following MOWHTO (odds ratio 4.911, 95% confidence interval 1.820-13.256, P < .01).

CONCLUSION

Severe medial OA was an independent risk factor for dissatisfaction following contemporary MOWHTO using a rigid locking plate. Surgeons should take this into consideration when counseling and choosing surgical options in MOWHTO candidates with severe medial OA.

LEVEL OF EVIDENCE

Level III.

Femoral offset guide facilitates accurate and precise femoral tunnel placement for single-bundle anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to compare the accuracy and precision of femoral tunnel placement by expert and novice surgeons using an offset guide for single-bundle ACL reconstruction via the anteromedial (AM) portal.

METHODS

Twenty-five single-bundle ACL reconstructions performed by a novice surgeon were matched with 25 ACL reconstructions performed by an expert surgeon, based on one-to-one propensity score matching. The same technique was used by both groups for femoral tunnel placement using a 7-mm offset guide through the AM portal. Using the Bernard and Hertel grid method for postoperative three-dimensional reconstructed computed tomography, the accuracy and precision of various tunnel positions were compared.

RESULTS

No differences were found between the proximal-distal and anterior-posterior femoral tunnel placements by the two groups (proximal-distal; 30.5% involving experts, and 32.5% by novices, n.s) (anterior-posterior; 32.6% involving experts, and 31.6% by novice, n.s). The accuracy of the femoral tunnel positions, based on the average distance from the tunnel center to the center of ACL direct insertion, was similar between the two groups (n.s). No differences were found between the groups in terms of precision of femoral tunnel positions (n.s).

CONCLUSION

Novice surgeons can achieve accuracy and precision comparable to experts in creating femoral tunnels via single-bundle ACL reconstruction through the AM portal using a femoral offset guide. We recommend the use of a femoral offset guide for ACL reconstruction during the learning phase of a novice surgeon for effective tunnel placement to reduce the learning curve required to perform accurate and reproducible ACL reconstruction.

LEVEL OF EVIDENCE

Case-control study, Level III.

Does non-contact or delayed contact of an adjustable-loop femoral button affect knee stability following anterior cruciate ligament reconstruction?

BACKGROUND

The purpose of this study was to investigate whether cortical non-contact or delayed contact of an adjustable-loop button for femoral fixation could affect knee stability following anterior cruciate ligament (ACL) reconstruction.

METHODS

Eighty subjects who underwent single-bundle ACL reconstruction using an adjustable-loop femoral cortical button were retrospectively reviewed regarding patient demographics, graft size, combined surgery, and postoperative 2-year results of knee stability, functional scores, and radiographic tunnel widening. We compared the contact and the non-contact groups determined by position of the button observed in immediate postoperative radiographs. According to 2-year postoperative radiographs, the non-contact group was further divided into two subgroups (delayed contact and persisting non-contact subgroups) and results were compared.

RESULTS

The contact group had 46 patients and the non-contact group had 34 patients. The average gap distance in the non-contact group was 1.9 ± 0.6 (1.1-3.4) mm. There were no significant differences in KT-1000 arthrometric knee stability (p = .667) or Lysholm score (p = .198), or International Knee Documentation Committee (IKDC) score (p = .091) between the two groups. No significant differences in tunnel widening were found at femoral and tibial tunnels on anteroposterior and lateral radiographs (p > .1, all tunnels). In addition, delayed contact subgroup and persisting non-contact subgroup showed similar radiographic and clinical outcomes.

CONCLUSION

Surgeons should strive to obtain cortical contact of the adjustable-loop femoral button. Nevertheless, cortical non-contact with less than 3 mm of gap distance did not affect knee stability, radiographic outcomes, or clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Degree of Preoperative Subchondral Bone Marrow Lesion Is Associated With Postoperative Outcome After Medial Opening Wedge High Tibial Osteotomy

BACKGROUND

In osteoarthritis of the knee, subchondral bone marrow lesion (BML) is known to be significantly associated with the severity of pain. However, little is known about the influence of preoperative BML on postoperative outcomes after medial opening wedge high tibial osteotomy (MOWHTO).

PURPOSE

To compare patient-reported outcomes for those who underwent MOWHTO according to the severity of BML based on magnetic resonance imaging.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 136 patients who underwent MOWHTO between June 2011 and May 2016 with clinical and radiologic assessments before and after surgery were retrospectively enrolled. Patients were divided into 2 groups according to the presence or absence of BMLs. They were then subdivided into 4 or 3 groups based on the sum of BML scores of the medial femoral condyle and tibial plateau according to MRI (magnetic resonance imaging) Osteoarthritis Knee Score or Filardo classification, respectively. Associations between the severity of BML and postoperative 1- and 2-year Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) subscores were evaluated through linear regression analysis. At postoperative 2 years, the rate of patients having a WOMAC score improvement of 15 points based on minimum clinically important difference and patient satisfaction were compared between groups.

RESULTS

BMLs were present in 96 (70.6%) of 136 cases. There were no significant differences in demographics or radiographic variables between groups according to the presence/absence or severity of BMLs (all P > .05). There was a significant association between preoperative or 1-year postoperative WOMAC pain/function score and the extent or intensity of BMLs (all P < .05). After adjusting for age, body mass index, osteoarthritis grade, and hip-knee-ankle angle, the significance persisted in the association between the extent or intensity of BMLs and WOMAC pain/function score at 1 year after surgery (all P < .05). However, a significant association was not found at postoperative 2 years (all P > .05). All groups showed similar rates of WOMAC score showing 15 points of improvement and satisfaction after MOWHTO (all P > .05). At 2 years after surgery, 82.5% of patients with BMLs were satisfied with their operation, as compared with 84.4% of those without BMLs (P = .801).

CONCLUSION

Although worse clinical outcomes were associated with severe BML during the recovery period, MOWHTO provided a high degree of clinical improvement on patient-reported outcomes regardless of the severity of BML at 2 years postoperatively.

Elongation Patterns of the Anterior and Posterior Borders of the Anterolateral Ligament of the Knee

PURPOSE

To compare the elongation patterns of the anterior and posterior borders of the anterolateral ligament (ALL) at varying knee flexion angles with the knee in a neutral position without any external forces and with external forces applied, including anterior-posterior translation, internal-external rotation, and varus-valgus angulation.

METHODS

Eight cadaveric knees were tested in a custom knee testing system. Elongation of the anterior and posterior borders of the ALL was measured using a MicroScribe 3DLX system at knee flexion angles of 0°, 30°, 60°, and 90° and after the application of internal-external rotation, anterior-posterior translation, and varus-valgus angulation.

RESULTS

The anterior border showed a slight noncontinuous increase in percentage elongation (0.8% ± 2.2%) whereas the posterior border showed a continuous decrease in percentage elongation (-12.0% ± 2.8%) as knee flexion increased (P < .001). Apart from the elongation of the posterior border at 90° of knee flexion, internal rotation, varus angulation, and anterior translation resulted in a significant increase in the percentage elongation of the anterior and posterior borders at each flexion angle compared with external rotation, valgus angulation, and posterior translation, respectively.

CONCLUSIONS

The ALL shows different elongation patterns between the anterior and posterior borders, with a continuous decrease in the percentage elongation of the posterior border as knee flexion increases.

CLINICAL RELEVANCE

This study presents useful evidence to resolve the uncertainty regarding the change in length of the ALL at various degrees of knee flexion. This information may be helpful for deciding the optimal knee flexion angle during ALL graft fixation. The findings from this study suggest that graft fixation during ALL reconstructions should be performed at close to full extension of the knee.

Kinematically aligned total knee arthroplasty reproduces more native rollback and laxity than mechanically aligned total knee arthroplasty: A matched pair cadaveric study

BACKGROUND

A growing body of evidence supports that kinematically aligned (KA) total knee arthroplasty (TKA) provides superior clinical outcomes and satisfaction than mechanically aligned (MA) TKA. In theory, KA TKA would restore knee kinematics closer to the native condition than MA TKA, but the current biomechanical evidence is lacking.

HYPOTHESIS

KA TKA would restore knee biomechanics to the native condition better than MA TKA.

METHODS

Seven pairs of cadavers were tested. For each pair, one knee was randomly assigned to KA TKA and the other to MA TKA. During KA TKA, the sizes of femur and tibia resections were equivalent to implant thickness to align with the patient-specific joint line. MA TKA was performed using conventional measured resection techniques. All specimens were mounted on a customized knee-testing system and digitized. Knee motions measured during flexion included rollback, axial tibiofemoral rotation, and laxities, specifically varus-valgus laxity, anterior-posterior translation, and internal-external rotation.

RESULTS

The pattern of knee motion following KA TKA was similar to the native knee. However, following MA TKA, both medial and lateral rollback and tibiofemoral axial rotation were decreased relative to those of the native knee. Valgus laxity was restored only after KA TKA, whereas varus laxity was restored only after MA TKA. Anterior translation was increased regardless of the alignment strategy. In addition, rotational laxities were restored after KA TKA, but external rotation laxity increased after MA TKA.

CONCLUSION

KA TKA restores femoral rollback and laxity to the native condition better than MA TKA. KA TKA may enhance functional performance and provide a more normal knee sensation.

LEVEL OF EVIDENCE

II, Controlled laboratory study.

Superficial and Deep Medial Collateral Ligament Reconstruction for Chronic Medial Instability of the Knee

There are several surgical techniques for medial collateral ligament reconstruction, including anatomic or nonanatomic medial knee reconstruction. Although the medial collateral ligament consists of the superficial medial collateral ligament (sMCL) and deep medial collateral ligament (dMCL), surgical procedures have only been described for reconstruction of the sMCL alone or reconstruction of the sMCL and posterior oblique ligament. The dMCL assists the knee in rotational stability, primarily in extension, moving into early flexion. We describe sMCL and dMCL reconstruction with semitendinosus and gracilis autografts using adjustable-length loop suspensory fixation devices for tibial fixation. By use of our technique, it is possible to provide good stability and satisfactory results for medial instability of the knee.

Predictive factors for satisfaction after contemporary unicompartmental knee arthroplasty and high tibial osteotomy in isolated medial femorotibial osteoarthritis

INTRODUCTION

Both high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are viable treatment options for early osteoarthritis (OA). Although a substantial proportion of the patient selection criteria for HTO and UKA are now shared, the factors related to satisfaction following each procedure remain unclear.

HYPOTHESIS

We hypothesized that patient factors associated with satisfaction following contemporary HTO and UKA would be different.

MATERIAL AND METHODS

We retrospectively reviewed the records of consecutively enrolled medial opening-wedge HTOs (n=123) and Oxford mobile-bearing UKAs (n=118) with satisfactory postoperative alignment. Preoperative demographics, physical activity levels, varus deformity status, and degree of OA were recorded. Postoperative radiographs, frequency of combined procedures and patient-reported outcomes (PROs) including pain, Western Ontario and McMaster Universities Osteoarthritis Index score, and patient satisfaction were assessed.

RESULTS

Severe OA (p<0.01) was associated with an increased risk of dissatisfaction following HTO, whereas young age (p<0.01) and severe varus deformity (p=0.045) were related to dissatisfaction after UKA. In addition, patient satisfaction following UKA was higher than that following HTO in individuals with highly physically demanding activity. All UKA PROs were superior to those of the HTO group, except pain level.

CONCLUSION

Despite the shared patient selection criteria for contemporary HTO and UKA, severe OA was associated with dissatisfaction following HTO, whereas young age and varus deformity were associated with dissatisfaction following UKA. Age, varus deformity and OA severity should be considered when deciding whether to perform HTO or UKA.

TYPE OF STUDY AND LEVEL OF PROOF

Retrospective cohort study, Level III.

Duloxetine Reduces Pain and Improves Quality of Recovery Following Total Knee Arthroplasty in Centrally Sensitized Patients: A Prospective, Randomized Controlled Study

BACKGROUND

Unexplained postoperative pain is one of the most feared complications of total knee arthroplasty (TKA). A persistent noxious peripheral stimulus, such as the pain of chronic knee osteoarthritis, can cause central sensitization in which the central nervous system becomes hyperexcitable, resulting in hypersensitivity to both noxious and non-noxious stimuli. Patients with central sensitization may be more susceptible to unexplained pain after TKA. Duloxetine, a selective serotonin norepinephrine reuptake inhibitor (SNRI), can ameliorate the pain associated with central sensitization, and we aimed to determine whether it could reduce postoperative pain and improve quality of recovery after TKA in patients with central sensitization.

METHODS

Patients undergoing TKA were screened for central sensitization preoperatively with use of the Central Sensitization Inventory (CSI). Among 464 patients with primary osteoarthritis who were scheduled for primary unilateral TKA, 80 were identified as being centrally sensitized and were included in the study. Forty patients were randomly assigned to the duloxetine group (30 mg 1 day before surgery and for 6 weeks after surgery), and 40 were randomized to the control group (no duloxetine). Pain and quality of recovery were assessed with use of the Brief Pain Inventory (BPI), the Short Form-36 (SF-36), the Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP), and the Hamilton Depression Scale. The prevalence of adverse medication effects was also noted.

RESULTS

The patients in the duloxetine group had better performance across pain metrics during the initial 2 to 12-week postoperative period (p < 0.05). The duloxetine group also had a superior quality of recovery 2 weeks after TKA, as indicated by emotional and physical functioning (all p < 0.05). There was no difference between groups in the prevalence of adverse events.

CONCLUSIONS

A substantial number of patients are centrally sensitized before TKA. Surgeons should consider selective incorporation of duloxetine into the multimodal postoperative analgesic protocol, according to the severity of central sensitization, to minimize the possibility of persistent pain following TKA.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Central sensitization is a risk factor for wound complications after primary total knee arthroplasty

PURPOSE

Postoperative wound complication is a significant risk factor for subsequent deep periprosthetic joint infection after total knee arthroplasty (TKA). Central sensitization is an abnormal enhancement of pain mechanism involving the central nervous system. Although psychological disorder is widely considered as a risk factor, the relationship between central sensitization and wound complication is currently unclear. Therefore, the purpose of this study was to investigate whether central sensitization was associated with high wound complication rate after primary TKA.

MATERIALS AND METHODS

Between January and June 2016, 161 patients undergoing unilateral TKA were prospectively divided into two groups based on central sensitization inventory score of 40 points after excluding cases with known risk factors such as physical comorbidities, health-related behaviors, and psychological disorders. Group 1 consisted of 112 patients (112 knees) whose central sensitization inventory score was < 40 points and group 2 consisted of 49 patients (49 knees) whose central sensitization inventory score was ≥ 40 points. Wound complications were defined as wound dehiscence, suture granuloma, prolonged wound oozing after postoperative day 5, significant hematoma formation, or surgical site infection recorded during the initial 90-day postoperative period. Demographic data, visual analog scale (VAS), central sensitization inventory score, and wound complications were compared between the two groups.

RESULTS

Wound complications developed in 3 (2.7%) knees in group 1 and 14 (28.6%) knees in group 2 (p < 0.001). Multivariate logistic regression analysis showed that the odds of postoperative wound complications were increased 15.7 times in patients with central sensitization inventory score ≥ 40 (95% CI 4.1-60.0, p < 0.001).

CONCLUSION

Central sensitization is a risk factor for the development of postoperative wound complication after primary TKA.

LEVEL OF EVIDENCE

II.

Use of All-polyethylene Tibial Components in Unicompartmental Knee Arthroplasty Increases the Risk of Early Failure

All-polyethylene (all-poly) tibial designs in primary total knee arthroplasty (TKA) have been reconsidered with excellent clinical outcomes, survivorship, and cost-effectiveness. However, whether all-poly tibial components provided comparable results to metal-backed modular components during unicompartmental knee arthroplasty (UKA) remains unclear. This study compared the clinical outcomes and prevalence of early failure between all-poly and metal-backed modular components in UKA. We retrospectively reviewed the records and radiographs of 101 consecutive UKAs. In total, 51 UKAs were performed using all-poly tibial components; 50 others used metal-backed modular components. Clinical and radiographic outcomes, adaptive bone remodeling assessed by radiographic bone density, and early failure prevalence rates were compared. Despite a lack of group differences in clinical and radiographic outcomes (p > 0.1 in all comparisons), adaptive bone remodeling at 2 years after surgery of all-poly UKAs was more progressive compared with metal-backed UKAs (1.2 in all-poly UKA group vs. 0.9 in metal-backed UKA group, p < 0.001). In addition, 6 of 51 all-poly UKAs failed within 2 years postoperatively, whereas no metal-backed UKAs failed (11% in all-poly UKA group vs. 0% in metal-backed UKA group, p = 0.027). All-poly tibial component use during UKA increased the risk of early failure, which may be due to a failure in tibial loading distribution.

Intraoperative adjustment of alignment under valgus stress reduces outliers in patients undergoing medial opening-wedge high tibial osteotomy

INTRODUCTION

A considerable percentage of outliers with under- or over-correction continue to be reported despite precise preoperative planning and cautious intraoperative correction of lower limb alignment in medial opening-wedge high tibial osteotomy (MOWHTO). The purpose of this study was to determine whether our novel technique for the intraoperative adjustment of alignment under valgus stress reduces the number of outliers in patients undergoing MOWHTO compared to the conventional technique, which corrects alignment according to the cable method only.

MATERIALS AND METHODS

One hundred seventeen consecutive knees were enrolled in this case-control study. The first 52 knees (51 patients) were corrected in accordance with preoperative plans using the Dugdale method with modification with an intraoperative cable (group 1). In the other 65 knees (60 patients), the angle was corrected using the Dugdale method and limb alignment was adjusted using the intraoperative cable technique by applying valgus stress to the knee joint (group 2). The postoperative weight bearing line ratios and mechanical axis of the lower limb were compared at postoperative one year. Each knee was evaluated according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score preoperatively and at postoperative one year.

RESULTS

A significant reduction in the number of outliers was seen in group 2 compared to group 1 (group 1 = 48.1%, group 2 = 9.2%, p < 0.001). Nineteen of 52 knees (36.5%) were under-corrected in group 1, whereas 6 of 65 knees (9.2%) were under-corrected in group 2 (p < 0.001). Six of 52 knees (11.6%) were over-corrected in group 1, whereas 0 of 65 knees (0.0%) were over-corrected in group 2 (p = 0.005). At one -year after operation, group 2 showed significantly lower WOMAC score than group 1 (p = 0.014).

CONCLUSIONS

Intraoperative adjustment of alignment under valgus stress significantly reduced the number of outliers compared to a technique that corrected alignment using the cable method in patients undergoing MOWHTO.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Posterior Cruciate Ligament Reconstruction with Retrograde Femoral Technique, Posterior Trans-septal Portal and Full Tibial Tunnel

Suspensory femoral graft fixation has been a popular and reliable method in anterior cruciate ligament (ACL) reconstruction. Some authors have introduced suspensory femoral fixation in posterior cruciate ligament (PCL) reconstruction using inside-out (IO) technique. The use of IO technique for femoral tunnel preparation could significantly sharpen the critical corner, which might result in graft failure. A retrograde drilling pin that recently has been popular in ACL reconstruction allows "no incision" in the outside-in (OI) technique for the creation of a femoral socket. Here we describe the suspensory femoral fixation using a retro-socket technique in single-bundle PCL reconstruction. By using this technique, it is possible to create a retrograde femoral socket for suspensory femoral fixation in an OI manner in a desirable direction and reduce angulation of the graft in the entry area of the femoral tunnel.

Collagen Augmentation Improves the Quality of Cartilage Repair After Microfracture in Patients Undergoing High Tibial Osteotomy: A Randomized Controlled Trial

BACKGROUND

The quality of cartilage repair after marrow stimulation is unpredictable. To overcome the shortcomings of the microfracture technique, various augmentation techniques have been developed. However, their efficacies remain unclear.

HYPOTHESIS

The quality of cartilage repair and clinical outcomes would be superior in patients undergoing high tibial osteotomy (HTO) with microfracture and collagen augmentation compared to those undergoing HTO with microfracture alone without collagen augmentation for the treatment of medial compartment osteoarthritis (OA) of the knee.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Twenty-eight patients undergoing HTO were randomized into 2 groups: microfracture alone (group 1, n = 14) or microfracture with collagen augmentation (group 2, n = 14). At 1 year postoperatively, second-look arthroscopic surgery and biopsy of repaired cartilage were performed at the time of HTO plate removal. Biopsy specimens were graded using the International Cartilage Repair Society Visual Assessment Scale II (ICRS II). In addition, imaging outcomes in terms of the magnetic resonance observation of cartilage repair tissue (MOCART) score were assessed based on magnetic resonance imaging (MRI). Finally, clinical outcomes in terms of the visual analog scale (VAS) for pain score, Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) score, and Tegner activity scale score were evaluated.

RESULTS

The mean ICRS II score in group 2 was significantly higher than that in group 1 (1053.2 vs 885.4, respectively; P = .002). Group 2 showed greater improvement in tissue morphology, cell morphology, surface architecture, middle/deep zone assessment, and overall assessment compared with group 1 ( P < .050 for all comparisons). Imaging outcomes based on the MOCART score were superior in group 2 compared to those in group 1 on MRI at 1 year postoperatively (64.6 vs 45.4, respectively; P = .001). The degree of defect repair was better in group 2 than in group 1 ( P = .040). Clinical outcomes in terms of the VAS for pain score, KOOS, IKDC score, and Tegner activity scale score were improved in both groups without between-group differences ( P > .100 for all comparisons).

CONCLUSION

The quality of cartilage repair after microfracture with collagen augmentation was superior to that after microfracture alone in patients undergoing HTO. Clinical results after 1 year did not reflect this difference in tissue repair. Therefore, a longer follow-up of the cohort is needed to answer this question.

Femoral Nerve Block versus Adductor Canal Block for Analgesia after Total Knee Arthroplasty

Inadequate pain management after total knee arthroplasty (TKA) impedes recovery, increases the risk of postoperative complications, and results in patient dissatisfaction. Although the preemptive use of multimodal measures is currently considered the principle of pain management after TKA, no gold standard pain management protocol has been established. Peripheral nerve blocks have been used as part of a contemporary multimodal approach to pain control after TKA. Femoral nerve block (FNB) has excellent postoperative analgesia and is now a commonly used analgesic modality for TKA pain control. However, FNB leads to quadriceps muscle weakness, which impairs early mobilization and increases the risk of postoperative falls. In this context, emerging evidence suggests that adductor canal block (ACB) facilitates postoperative rehabilitation compared with FNB because it primarily provides a sensory nerve block with sparing of quadriceps strength. However, whether ACB is more appropriate for contemporary pain management after TKA remains controversial. The objective of this study was to review and summarize recent studies regarding practical issues for ACB and comparisons of analgesic efficacy and functional recovery between ACB and FNB in patients who have undergone TKA.