Cutaneous Hypesthesia and Kneeling Ability After Total Knee Arthroplasty: A Randomized Controlled Trial Comparing Anterolateral and Anteromedial Skin Incision

The objective measurement of hypoaesthesia after Total Knee Arthroplasty and its correlation with skin incision length: a prospective study

PURPOSE

This study aims to measure the peri-incisional numbness developing after Total Knee Arthroplasty (TKA) performed using the midline skin incision. It studies the natural course of the numbness and determines its correlation with the skin incision length (SIL).

MATERIALS & METHODS

66 knees undergoing primary TKA with a standard midline incision were evaluated. The SIL and the area of numbness (AON) were measured in complete knee extension and 90° of flexion. The area was marked by the patient using a sketch pen and then determined by an independent observer using monofilament testing. The "ImageJ" software was used to calculate the area.

RESULTS

All patients developed numbness around the knee after TKA. There was a statistically significant correlation between the SIL and AON in both flexion and extension at two weeks (p < 0.001) and three months (p < 0.001). However, there was a weak and insignificant correlation at six months (p = 0.217).

CONCLUSION

When TKA is performed using the midline skin incision, the SIL positively correlates with the AON postoperatively during the initial short-term follow-up. At six monthly follow-ups, there is no significant correlation between the two.

Are Orthopaedic Clinical Trials Linguistically and Culturally Diverse? A Systematic Review

Purpose

Underrepresentation and misrepresentation of historically underrepresented populations in randomized controlled trials (RCTs) may have implications for the validity of research results and their application for diverse populations. To evaluate the representation of historically linguistically, racially, and ethnically underrepresented participants in orthopaedic randomized controlled trials (RCTs) and to assess the use of translated and culturally adapted patient reported outcome measures (PROMs).

Methods

Separate and comprehensive literature searches of PubMed, Web of Science, and Embase databases were performed to identify RCTs utilizing PROMs between the years 2012 - 2022 among the top five highest 5-year impact factor orthopaedic journals according to the 2021 Journal Citation Reports database. The primary outcomes of interest included reporting of linguistic, racial and ethnic demographic characteristics of trial participants and the utilization of translated PROMs. The methodological quality of each clinical trial was assessed using the Jadad Criteria.

Results

230 RCTs met inclusion criteria. The language of participants was reported in 14% of trials and in 17% of trials when searching both the published text and clinical trial registration information. In addition, race and/or ethnicity was reported in 11% of trials, and the use of translated PROMs was reported in 7% of trials. Among the six multinational studies, none reported the language of the study population nor the use of translated PROMs. Notably, four studies (2%) reported utilizing culturally adapted PROMs. The average Jadad score was 3.07.

Conclusion

Participant language, race, and ethnicity are infrequently reported in orthopaedic clinical trials, potentially limiting the application and interpretation of study results. Similarly, the linguistic and cultural adaptation of PROMs utilized are often not reported, which also limits interpretations of the validity and generalizability of orthopedic study results. Researchers and journals should promote standard reporting of demographic data and methods of PROM adaptation to ensure results are generalizable to diverse patient populations.

Level of Evidence

III.

Moving a skin incision to lateral side of tibial tubercle reduces the risk of persistent skin numbness compared with a regular midline one: A randomized paired study in bilateral total knee arthroplasty

BACKGROUND

The midline incision during total knee arthroplasty (TKA) is known to damage the infrapatellar branch of the saphenous nerve (IPBSN), leading to lateral flap numbness. The aim was to evaluate the rate of persistent skin numbness (RSN) and area of skin numbness (AON) after a lateral-based skin incision compared with the standard midline incision in bilateral TKA patients.

METHODS

Thirty-six patients undergoing bilateral TKA were included and randomly assigned to receive the lateral skin incision (lateral side of the tibial tubercle) on one knee and the standard midline incision on the contralateral. All other surgical steps were identical. Primary outcomes were the RSN at 1 year and the AON at 6 weeks, 3, 6, and 12 months postoperatively. Kneeling ability test (KAT), operative time, and length of incision were also recorded.

RESULTS

The lateral incision had half the RSN at 12 months compared to the midline incision (25% vs 53%; p = 0.01). The median AON at 1-year after surgery was 0 [0-0.5] cm2 in lateral incision vs 4 [0-7.5] cm2 in midline group (p < 0.001). KAT was minimally better in the lateral group at 110° of kneeling between 6-month to 1-year. Operative time and length of incision were similar between both groups.

CONCLUSION

The lateral skin incision reduced RSN by approximately 50% compared with the midline incision. The AON in lateral incision was 4 cm2 smaller than midline at 1-year after surgery. Moving a skin incision more lateral may be considered to minimize the numbness after TKA.

Skin sensory alteration and kneeling ability following cruciate retaining total knee arthroplasty are not affected by the incision position: A randomised controlled trial of simultaneous bilateral surgery

PURPOSE

The purpose of this randomised controlled trial was to assess the impact of skin incision location on the patients' ability to kneel.

METHODS

A total of 29 patients undergoing bilateral total knee arthroplasty (58 knees) were randomised to receive a lateral or midline incision, with the contralateral limb receiving the alternative option. Cruciate retaining implants were used in all cases by three experienced arthroplasty surgeons. The primary outcome measures assessed functional ability to kneel using an innovative five-point kneeling scale, preferred knee to kneel on and the area of cutaneous sensory loss around the incision at 6 weeks, 6 months and 12 months. Secondary outcome measures were the OKS, KOOS JR, FJS and EQ5D patient reported outcome measures (PROMS), length of surgical scar, overall knee preference and range of motion (ROM).

RESULTS

There were no significant differences between the two groups for any primary or secondary outcome measures. Flexion range however, had a significant positive correlation with kneeling score (r = 0.335, p = 0.010). The kneeling score increased at each time point after surgery and was significantly greater at 12 months than preoperatively (2.7 v 3.5, p = 0.015). The area of sensory loss lateral to the incision was significantly less at 6 and 12 months than at 6 weeks (43.6cm2 and 40.1cm2 v 84.1cm2, p < 0.0001).

CONCLUSION

The ability to kneel following cruciate retaining total knee arthroplasty is not affected by the incision position but by time and flexion range. TKA improves the ability to kneel by 12 months post-surgery. Sensory loss lateral to the incision reduces with time.

LEVEL OF EVIDENCE

Therapeutic Level 2.

Femoral prosthesis alignment of augmented reality-assisted versus accelerometer-based navigation in total knee arthroplasty: A noninferiority analysis

INTRODUCTION

The purpose of this study was to examine the comparative precision of the augmented reality (AR)-assisted navigation system and the accelerometer-based navigation system in total knee arthroplasty (TKA).

MATERIALS AND METHODS

We performed noninferiority analysis in a retrospective cohort. The coronal alignment of femoral prosthesis was compared between 109 TKAs performed using the AR-assisted navigation system and 118 TKAs performed using the accelerometer-based navigation system. All femoral prostheses were planned to be positioned perpendicular to the mechanical axis of the femur. The primary outcome was the success rate of coronal alignment of the femoral prosthesis defined as alignment error relative to neutral alignment <3°. We calculated the noninferiority margin as 7%-points using the 95%-95 % method and also confirmed the validity of the noninferiority margin using the fixed margin method. Noninferiority would be shown if the lower boundary of the 95 % confidence interval (CI) for the between-group difference in percentage of the success rate was not less than 0.93 (i.e., 1.00 - 0.07).

RESULTS

Treatment success was achieved in 104 of 109 patients (95.4 %) in the AR-assisted navigation group and 110 of 118 (93.2 %) in the accelerometer-based navigation group. The risk ratio of success between the AR-assisted navigation group versus accelerometer-based navigation group was 1.02 (95 % CI, 0.96 to 1.09): the CIs did not include the noninferiority margin of 0.93.

CONCLUSION

The AR-assisted navigation system was noninferior to the accelerometer-based navigation system in terms of coronal alignment of the femoral prosthesis in TKA.

Patellar resurfacing and kneeling ability after total knee arthroplasty: a systematic review

BACKGROUND

Difficulty kneeling following total knee arthroplasty (TKA) remains highly prevalent, and has cultural, social, and occupational implications. With no clear evidence of superiority, whether or not to resurface the patella remains debatable. This systematic review examined whether resurfacing the patella (PR) or not (NPR) influences kneeling ability following TKA.

METHODS

This systematic review was conducted by following PRISMA guidelines. Three electronic databases were searched utilizing a search strategy developed with the aid of a department librarian. Study quality was assessed using MINROS criteria. Article screening, methodological quality assessment and data extraction were performed by two independent authors, and a third senior author was consulted if consensus was not reached.

RESULTS

A total of 459 records were identified, with eight studies included in the final analysis, and all deemed to be level III evidence. The average MINORS score was 16.5 for comparative studies and 10.5 for non-comparative studies. The total number of patients was 24,342, with a mean age of 67.6 years. Kneeling ability was predominantly measured as a patient-reported outcome measure (PROM), with two studies also including an objective assessment. Two studies demonstrated a statistically significant link between PR and kneeling, with one demonstrating improved kneeling ability with PR and the other reporting the opposite. Other potential factors associated with kneeling included gender, postoperative flexion, and body mass index (BMI). Re-operation rates were significantly higher in the NPR cohort whereas PR cohorts had higher Feller scores, patient-reported limp and patellar apprehension.

CONCLUSION

Despite its importance to patients, kneeling remains not only under-reported but also ill-defined in the literature, with no clear consensus regarding the optimum outcome assessment tool. Conflicting evidence remains as to whether PR influences kneeling ability, and to clarify the situation, large prospective randomized studies are required.

Neuropathy Dermatitis: An Underdocumented Complication Following Total Knee Arthroplasty

Background

Midline surgical incision used in Total Knee Arthroplasty (TKA) is associated with iatrogenic injury to the infrapatellar branch of the saphenous nerve, which leads to neuropathic dermatitis around the healed surgical scar. There are very few studies with a limited number of cases that have reported this complication. We evaluated the incidence of neuropathic dermatitis and its implication for the functional outcome in TKA patients.

Methodology

Patients who underwent primary TKA between 1 January 2010 and 31 August 2019 and presented in follow-up with sensory disturbances and skin lesions adjacent to the surgical incision were evaluated in this study.

Results

A total of 3318 patients with 4282 TKAs were included, of which 188 patients presented with the clinical picture of neuropathic dermatitis. There were 136 females and 52 males with a mean age of 67.13 years (range 37-92 years). The mean duration from surgery to the appearance of skin lesions was 4.4 months (range 2-6 months), and they resolved at a mean duration of 7.67 (range 6-12) weeks. In our study, we found an incidence of 5.52%. All these patients had a stable and well-functioning knee at the time of presentation of the lesion with a mean Knee Society Score (KSS) of 92 (range 84-96).

Conclusion

In our study, we found the incidence of neuropathic dermatitis to be 5.52%, without any long-term implication on the functional outcome of operated knees. For a self-limiting complication of midline knee incision of TKA, it either resolves on its own or requires a short duration of topical steroid application.

Numbness Following Total Knee Arthroplasty: Role of Incision Length And Position - A Randomized Study

Background

One of the symptoms annoying patients after total knee replacement (TKR) is numbness around the operative scar. Some studies have shown that altering the incision in terms of placement or length may decrease the incidence of numbness. It still remains unknown whether numbness affects patient-reported outcomes.

Methods

We conducted a randomized study to compare a short-length incision (n = 50) and a lateral exit incision (n = 50) with a standard midline TKR incision (n = 50) in terms of the incidence of numbness and its progress over 1 year of follow-up. Our secondary objective was to look at the involved zone, area of numbness, and secondary symptoms. We also looked at patient-reported outcome in terms of satisfaction in all groups using a visual analog scale and Forgotten Joint Score.

Results

At 3 months postoperatively, the incidence of numbness was least in the lateral exit group: 46.2% as compared to midline (62%) and short (58.3%), but the difference was not significant (p = 0.07). At 6 months, the short incision group had a significantly lower incidence (8%) of residual numbness as compared to 30% in the other two groups (p = 0.003). At 1 year, most patients recovered sensation loss and had similar function.

Conclusions

Placement or length of an incision did not significantly affect the incidence of numbness; however, the short incision led to early recovery of numbness. At 1 year of follow-up, most patients did not complain of loss of sensation and had similar functional outcome.

Is the Numbness after Knee Replacement a More Critical Complication Than Thought? A Detailed Analysis of Neuropathic Pain and Functional Outcomes

Background and Objectives: Numbness, one of the complications after knee replacement (KR), has been studied far less than other complications, and there are few studies on this topic. Without comprehensive research on numbness, there is a need to design a study that includes all relevant parameters. This study investigated the relationship between numbness and pain and neuropathic pain and its impact on functional and emotional life and the functioning of the knee. Materials and Methods: The 105 knees with KRs were divided anteriorly into six regions. Numbness was determined with a pinprick test. Douleur Neuropathique 4 (DN4) and a painDETECT questionnaire (PD-Q) were tested for neuropathic pain. Patients’ physical, emotional, and social status and functional knee abilities were assessed with the Short Form (SF-36) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) test. The relationships between numbness and gender, age, bilaterality, postoperative follow-up time, and incision measures were examined. The binomial logistic regression model was applied to investigate the effects of age, gender, bilaterality, incision length, and postoperative follow-up time on numbness. Results: A total of 88.6% of the patients were female, half had bilateral KRs, and the mean age was 68.3 years. Numbness occurred more frequently in the L3 and L2 areas than in other regions. There was no association with gender, bilaterality, and age, but there was a weak association with postoperative follow-up time. There was a positive correlation between numbness and neuropathic pain. It has been found that there is a significant relationship between numbness and physical function, and it has a negative effect. Emotional health was not significantly associated with numbness. The effect of numbness on social functioning was statistically significant. Knee functioning was measured with the WOMAC, and significant differences were found in the numbness group. Conclusions: According to the results, numbness is considered to be a complication that affects social and physical life and has a negative impact on functional outcomes of the knee. The results show that it should be considered a statistically significant complication. Numbness and its indirect effects should be considered in patients whose follow-up parameters are normal over one year but whose symptoms do not resolve.

Correlation of patient-reported numbness around surgical scars with patient-reported outcome measures and joint awareness after knee replacement: a cohort study

Background

Knee replacement is a very effective and indispensable treatment option for end-stage knee arthritis, and the number of cases has been increasing worldwide. A replaced knee joint without patient joint awareness is thought to be the ultimate goal of artificial knees. Joint awareness reportedly correlates with patient satisfaction. Although numbness around a replaced knee is a minor but common problem, its effect on postoperative outcome is controversial. Joint awareness also is sensitive to subtle abnormalities of the joint, so it must be negatively affected by numbness. Although numbness is minor, it cannot be ignored to further improve knee replacement outcomes. This study investigated the relationship between patient-reported numbness and other patient-reported outcome measures (PROMs), including joint awareness, and kneeling. We developed a numbness score based on a 5-point Likert scale on frequency of numbness, with an intraclass correlation coefficient of 0.76 and higher scores indicating less numbness.

Methods

The numbness score, New Knee Society Score (KSS), Knee Injury and Osteoarthritis Outcome Score (KOOS), Forgotten Joint Score-12 (FJS-12), and other clinical and radiological data from 311 patients (394 primary knee replacements) were analyzed. Kneeling ability was evaluated by using kneeling-specific items in the KSS (KSS-Kneeling).

Results

No numbness was found in 170 knees (43.1%), and some degree of numbness was found in the remaining 224 knees (56.9%). The numbness score showed weak-to-moderate correlations with KSS-Symptoms (r = 0.44), KSS-Satisfaction (r = 0.41), KSS-Activities (r = 0.29), and all KOOS subscales (r = 0.23–0.44), and FJS-12 (r = 0.42). Multiple regression analyses suggested that midline incision positively affected the numbness score over the anteromedial incision (p = 0.04) and that a better numbness score (p = 0.001), male sex (p < 0.0001), and better postoperative knee flexion angle (0.04) positively affected kneeling.

Conclusions

The numbness score positively correlated with PROMs and positively affected kneeling. Knee replacements performed via an anteromedial incision may be at higher risk for numbness.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04971-6.

Surgery-related predictors of kneeling ability following total knee arthroplasty: a systematic review and meta-analysis

Purpose

Kneeling ability is among the poorest outcomes following total knee arthroplasty (TKA). The purpose of this meta-analysis was to: (1) quantify kneeling ability after TKA; (2) identify surgical approaches and prosthesis designs that improve kneeling ability following TKA; and (3) quantify the effectiveness of these approaches.

Methods

We performed a systematic review in accordance with the PRISMA guidelines of multiple medical databases. Data relating to demographics, TKA technique, prosthesis design, and kneeling-specific outcomes were extracted. Comparative outcomes data were pooled using a random effects model.

Results

Thirty-six studies met the eligibility criteria. The proportion of patients able to kneel increased with longer follow-up (36.8% at a minimum of 1 year follow-up versus 47.6% after a minimum of 3 years follow-up, p < 0.001). The odds of kneeling were greater for patients undergoing an anterolateral incision compared with an anteromedial incision (OR 3.0, 95% CI 1.3–6.9, p = 0.02); a transverse incision compared with a longitudinal incision (OR 3.5, 95% CI 1.4–8.7, p = 0.008); and a shorter incision compared with a longer incision (OR 8.5, 95% CI 2.3–30.9, p = 0.001). The odds of kneeling were worse for a mobile prosthesis compared with a fixed platform design (OR 0.3, 95% CI 0.1–0.7, p = 0.005).

Conclusion

A large majority of patients are unable to kneel following TKA, although the ability to kneel improves over time. This evidence may facilitate preoperative patient counseling. Variations in choice of incision location and length may affect ability to kneel; however, high-quality randomized trials are needed to corroborate our findings.

Incidence, Injury Mechanisms, and Recovery of Iatrogenic Nerve Injuries During Hip and Knee Arthroplasty

Iatrogenic nerve injury is a rare but potentially devastating complication in total joint arthroplasty of the hip and the knee. Multiple previous studies have evaluated the incidence, mechanisms of injury, recovery, and potential treatments for this complication. Injury in total hip arthroplasty generally involves direct injury of sensory nerves from the incision, direct or traction injury of during exposure, or limb lengthening. Injury in total knee arthroplasty generally involves direct injury of sensory nerves from incision, injury due to errant placement of retractors, during balancing, or from traction because of deformity correction. Treatment of iatrogenic nerve injuries has ranged from observation, intraoperative prevention by nerve monitoring, limb shortening postoperatively, medications, and decompression. The orthopaedic surgeon should be versed in these etiologies to advise their patients on the incidence of injury, to prevent occurrence by understanding risky intraoperative maneuvers, and to select appropriate interventions when nerve injuries occur.

Modified anterior midline approach to treat hyperextension bicondylar tibial plateau fractures: Surgical technique and clinical experience with 18 cases

BACKGROUND

We evaluated the modified anterior midline approach and its efficacy for hyperextension bicondylar tibial plateau (HEBTP) fractures.

METHODS

From 2015 to 2019, 18 patients with HEBTP fractures with just little posterior cortical displacement were treated using the modified anterior midline approach. The operative protocols are fully described in this article, and the following parameters: articular step-off height (ASH), posterior tibial slope angle (pTSA), and medial tibial plateau angle (mTPA) were measured perioperatively and at the final follow-up. We also recorded the Rasmussen score and range of motion (ROM) to assess knee joint function at the final follow-up.

RESULTS

No complications, such as percutaneous nerve damage, infection, skin necrosis, and internal fixation breakage or loosening occurred perioperatively. The mean time for bony union was 13.7 weeks, and the mean preoperative ASH of the anterior cortex was 4.49 mm; this was restored to its normal height after surgery. The mean preoperative pTSA and mTPA were - 5.89° and 81.69°, respectively, compared with 3.89° and 87.91°, respectively, postoperatively. Comparing the postoperative and final follow-up radiographs, there were no significant differences in ASH, pTSA, and mTPA (P < 0.05). The average Rasmussen score was 27.2 (range, 23-29) at the final follow-up. Excellent results were achieved in 14 (77.8%) patients and good in 4 (22.2%) patients. The mean ROM in flexion was 123.2° and 2.9° in extension at the final follow-up.

CONCLUSIONS

This study suggested that the modified anterior midline approach is a reasonable alternative for HEBTP fracture repair.

Autonomic Denervation Dermatitis: A Relatively Undocumented 'ADD'itional Complication of Total Knee Replacements and Other Surgeries Around the Knee

BACKGROUND

Infrapatellar branch of the saphenous nerve lies subcutaneously and supplies the anterolateral aspect of knee below the patella. It is extremely susceptible to iatrogenic injuries during the surgeries around the knee, mainly total knee replacements (TKRs). Post operatively the patients present with localised area of numbness and in some instances a traumatic eczematous reaction termed autonomous denervation dermatitis (ADD) is witnessed, leading to skin manifestations that range from a simple rash to extensive lesions.

METHODOLOGY

A review of literature was conducted with search of relevant articles from Medline (PubMed), Embase, and Scopus which discussed eczematous skin lesions secondary to total knee replacements. Additionally, we noted studies which described these lesions in other surgeries around the knee like arthroscopies and fracture fixations.

RESULTS

Eight studies including atleast one case after TKR were reviewed. There was only one cohort study while the remaining included case reports and small case series. There were 69 cases of ADD appearing after TKR. The appearance of the skin lesions was lateral to the incision in 30/34 operated knees and on both sides of the incision in four knees after TKRs. Bilateral lesions were seen in only six patients of TKRs. There was no functional limitation caused by these lesions and they resolved either spontaneously or after using topical steroids.

CONCLUSION

ADD is a relatively uncommonly reported complication of TKRs, which can reduce patient satisfaction and increase surgeon apprehension. Although all cases of nerve damage do not manifest as cutaneous lesions, steps to minimise the damage to the nerve intra operatively should be taken. The diagnosis requires a high index of suspicion, and should not be dispelled as a simple allergic reaction without adequate investigations. Patients should be counselled to alleviate unnecessary fear and apprehensions.

The Effect of Sensory Deficit After Total Knee Arthroplasty on Patient Satisfaction and Kneeling Ability

Background

Skin numbness after total knee arthroplasty is a common complication. The incidence in the literature is variable from 27% to 100%. However, there is conflicting evidence about the consequences of this complication. The purpose of this study was to evaluate if postoperative numbness influenced patient satisfaction or kneeling ability.

Methods

We recruited patients who underwent a total knee arthroplasty for osteoarthritis one to 5 years before the study. Sensation was measured using a Semmes-Weinstein, 10-gram monofilament. Measurements were taken in several zones around the incision, and overall sensory status was classified as full numbness, partial numbness, and no numbness. Patients completed a questionnaire evaluating their subjective numbness, overall satisfaction, and kneeling ability. We evaluated the effect of numbness on satisfaction and function.

Results

A total of 96 patients were enrolled. Thirty-four patients were classified as no sensory deficit, 29 as partial deficit, and 33 as full deficit. There were no differences in demographics. Out of all the patients that were found to have a sensory deficit, 54.8% of them did not report any subjective numbness. Average patient-reported satisfaction scores were 8.76/10, 8.97/10, and 8.48/10 for no numbness, partial numbness, and full numbness, respectively. Eleven out of 96 patients noted an inability to kneel. There was no statistical difference for satisfaction scores or kneeling ability between the groups.

Conclusion

Sensory deficit after total knee arthroplasty is a frequently reported complication. However, the majority of the patients do not report subjective sensory deficits. Postoperative numbness does not appear to affect patient satisfaction or kneeling ability.

Numbness after medial unicompartmental knee arthroplasty: Prevalence and effect on functional outcome

BACKGROUND

The prevalence of skin sensation alteration after total knee arthroplasty is well established but less so in medial unicompartmental knee arthroplasty (MUKA). The aim of this study was to determine the prevalence, extent of numbness and its effect on mid-term functional outcomes after MUKA.

METHODS

A level 2 prospective cohort study was conducted. Twenty patients (21 knees) were recruited. Demographics, length of surgical incision and the thigh-to-calf ratio was recorded. At the 1-year postoperative period, the extent of numbness was measured using a quantifiable grid-based system for both pinprick and fine touch. Preoperative, 3 months and 1 year postoperative Knee Society Scores (KSS) and 36-Item Short Form Health Survey (SF-36) scores were recorded.

RESULTS

At the 1-year postoperative period, the prevalence of numbness to both fine touch and pin prick was 58% and 66%, respectively. The mean area of numbness to fine touch and pin prick was 336 mm² and 521 mm²_, respectively. The prevalence and extent of numbness was not significantly associated with surgical factors such as incision length and thigh-to-calf ratio. Prevalence and extent of numbness was not significantly associated with SF-36 scores and KSS at the 1-year postoperative period.

CONCLUSIONS

There is a high prevalence of numbness around the knee 1 year after MUKA. Surgical incision length and thigh-to-calf ratio was not associated with the extent of numbness. The presence and extent of numbness did not affect functional outcomes scores at the 1-year postoperative period. This study finding allows for accurate preoperative counselling with regards to numbness and its effects for patients undergoing MUKA.

Overview of Randomized Controlled Trials in Total Knee Arthroplasty (47,675 Patients): What Have We Learnt?

BACKGROUND

The aim of this study is to provide an overview of randomized controlled trials (RCTs) in primary total knee arthroplasty summarizing the available high-quality evidence.

METHODS

Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2019, Issue 3), Ovid MEDLINE, and Embase. We excluded nonrandomized trials, trials on unicompartmental knee arthroplasty or revision surgery, systematic reviews, and meta-analyses. Trials that met our inclusion criteria were assessed using a binary outcome measure of whether they reported statistically significant findings. These were then classified according to the intervention groups (surgical approach, tourniquet use, design, etc.).

RESULTS

Four hundred and three RCTs met the inclusion criteria and were included. The total number of patients in those 403 RCTs was 47,675. Only 33 RCTs (8.2%) reported significant differences between the intervention and the control groups. The trials were grouped into surgical approach 34, tourniquet 31, minimally invasive surgery 13, patient specific instrumentation 30, knee design 37, fixation 27, mobile bearing 47, navigation 50, polyethylene 19, technique 27, patella resurfacing 26, drain 19, closure 16, and others 27 RCTs.

CONCLUSION

For the vast majority of patients, a standard conventional total knee arthroplasty with a surgical approach familiar to the surgeon using standard well-established components, with or without tourniquet, without surgical drain leads to satisfactory long-term clinical outcomes.

Intraoperative Intravenous and Intra-Articular Plus Postoperative Intravenous Tranexamic Acid in Total Knee Arthroplasty: A Placebo-Controlled Randomized Controlled Trial

BACKGROUND

Combined intraoperative intravenous and intra-articular tranexamic acid (TXA) is 1 of the most effective administration routes to decrease the amount of perioperative blood loss during total knee arthroplasty (TKA). However, the additive effect of postoperative intravenous TXA administration remains unclear. We hypothesized that the postoperative repeated-dose intravenous administration of TXA would provide lower perioperative blood loss.

METHODS

We performed a double-blinded, placebo-controlled trial involving patients undergoing primary TKA. A total of 100 patients who were managed with combined intraoperative intravenous and intra-articular TXA were randomly assigned to receive 3 postoperative 1,000-mg doses of intravenous TXA (TXA group) or 3 postoperative doses of intravenous normal saline solution (placebo group) in a 1:1 ratio. The prespecified primary outcome was perioperative blood loss calculated from patient blood volume and the difference in hemoglobin from preoperatively to postoperative day 3. A post hoc power analysis showed that the number of patients allocated to either the TXA group (n = 46) or the placebo group (n = 54) possessed >80% power to detect a 200-mL difference in perioperative blood loss.

RESULTS

In the intention-to-treat analysis, we found no significant differences in perioperative blood loss between the TXA group and the placebo group through postoperative day 3 (578 ± 229 compared with 640 ± 276 mL, respectively; 95% confidence interval for the difference, -40 to 163 mL; p = 0.23). The prevalence of postoperative thrombotic events did not differ between the 2 groups (4.3% compared with 3.7%, respectively; p > 0.99).

CONCLUSIONS

Postoperative intravenous TXA had no additive effect in reducing perioperative blood loss in patients receiving intraoperative combined intravenous and intra-articular TXA.

LEVEL OF EVIDENCE

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

Incidence of Encountering the Infrapatellar Nerve Branch of the Saphenous Nerve During a Midline Approach for Total Knee Arthroplasty

The infrapatellar nerve branch (IPNB) of the saphenous nerve supplies cutaneous sensation to the anterolateral knee. Given its location and variable course, the IPNB is suspected to be at risk of injury with commonly used incisions around the knee. Nerve injury may lead to painful neuroma formation. To our knowledge, no study has evaluated the incidence at which the IPNB is encountered during the anterior approach incision for a routine total knee arthroplasty (TKA). The purpose of this study was to see whether the general joint arthroplasty surgeon can identify and examine the location of the IPNB encountered during primary TKA and to determine whether these branches would be transected during a standard medial arthrotomy.

The kneeling test is a valid method of assessing kneeling tolerance

PURPOSE

No quantitative test exists to reliably assess kneeling tolerance before and after surgery. The aim of this study was to validate a kneeling test, designed to quantify kneeling tolerance.

METHOD

A total of 179 participants (324 knees) were enrolled into the study, including 124 asymptomatic knees, 98 with osteoarthritis (OA), 85 following total knee arthroplasty (TKA) and 17 following anterior cruciate ligament reconstruction (ACLR). Patients were asked to kneel on a custom-built platform on a soft, firm and hard surface, at both 90° and 110° of knee flexion. A kneeling score of 0-100 was established for 90° and 110° with 100 being a complete absence of pain or discomfort. A linear mixed model with random intercept was used to estimate differences between conditions (healthy, OA, ACLR and TKA). Pearson's correlation coefficient was used to test the strength of the association between the kneeling test and the forgotten joint score (FJS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Test-retest reliability was estimated by the intraclass correlation coefficient (ICC).

RESULTS

The kneeling test demonstrated good discriminative validity with differences at 110° between asymptomatic knees and knees with OA (difference = - 42, p < 0.001), following ACLR (- 12, p = 0.013) and TKA (- 26, p < 0.001). Similar differences were observed at 90^°. The kneeling test demonstrated construct validity, with a moderately strong correlation observed between the kneeling test and the FJS and the WOMAC at 90° (FJS 0.474 [95%CI: 0.357, 0.577], WOMAC - 0.503 [- 0.389, - 0.602]) and 110° (FJS 0.579 [95% CI: 0.479, 0.665], WOMAC - 0.648 [- 0.560, - 0.722]). The ICC for the kneeling test at 90° and 110° was 0.843 (95% CI: 0.745, 0.905) and 0.926 (95% CI: 0.877, 0.956), respectively.

CONCLUSIONS

The kneeling test is a valid technique to quantitatively determine kneeling tolerance. It can aid in the assessment and modification of current surgical techniques to improve patient outcomes.

LEVEL OF EVIDENCE

III.

Intra-articular tranexamic acid as an adjunct to intravenous tranexamic acid for simultaneous bilateral total knee arthroplasty: a randomized double-blind, placebo-controlled trial

Background

Intra-articular tranexamic acid (TXA) as an adjunct to intravenous TXA was reported to decrease perioperative blood loss during unilateral total knee arthroplasty (TKA). However, there have been no randomized controlled trials comparing intravenous versus combined intravenous and intra-articular TXA administration in patients undergoing simultaneous bilateral TKA.

Methods

We randomly assigned 77 patients with 154 involved knees undergoing simultaneous bilateral TKA to the intravenous TXA group (intra-articular placebo for each knee) or combined TXA group (1000 mg of intra-articular TXA for each knee) with 1:1 treatment allocation. In both groups, 1000 mg of TXA was given intravenously twice, just before surgery and 6 h after the initial administration. Other perioperative medications, surgical procedures, and blood management strategies were the same for all patients. The primary outcome was perioperative blood loss calculated from blood volume and change in hemoglobin from preoperative to postoperative day 3.

Results

Intention-to-treat analysis showed no statistically significant differences in perioperative blood loss until postoperative day 3 (1067 ± 403 mL in the intravenous TXA group vs. 997 ± 345 mL in the combined TXA group [95% CI, − 240 to 100 mL], P = 0.42). No patients required allogenic blood transfusion. The incidence of thrombotic events did not differ between groups (12% in the intravenous TXA group vs. 9% in the combined TXA group; P = 0.73).

Conclusions

The addition of intra-articular TXA did not reduce perioperative blood loss in patients undergoing simultaneous bilateral TKA compared with placebo.

Trial registration

University Hospital Medical Information Network UMIN000026137. Registered 14 February 2017.

Kneeling ability after total knee replacement

Kneeling ability is consistently the poorest patient-rated outcome after total knee replacement (TKR), with 60-80% of patients reporting difficulty kneeling or an inability to kneel.Difficulty kneeling impacts on many activities and areas of life, including activities of daily living, self-care, leisure and social activities, religious activities, employment and getting up after a fall. Given the wide range of activities that involve kneeling, and the expectation that this will be improved with surgery, problems kneeling after TKR are a source of dissatisfaction and disappointment for many patients.Research has found that there is no association between range of motion and self-reported kneeling ability. More research is needed to understand if and how surgical factors contribute to difficulty kneeling after TKR.Discrepancies between patients' self-reported ability to kneel and observed ability suggests that patients can kneel but elect not to. Reasons for this are multifactorial, including knee pain/discomfort, numbness, fear of harming the prosthesis, co-morbidities and recommendations from health professionals. There is currently no evidence that there is any clinical reason why patients should not kneel on their replaced knee, and reasons for not kneeling could be addressed through education and rehabilitation.There has been little research to evaluate the provision of healthcare services and interventions for patients who find kneeling problematic after TKR. Increased clinical awareness of this poor outcome and research to inform the provision of services is needed to improve patient care and allow patients to return to this important activity. Cite this article: EFORT Open Rev 2019;4:460-467. DOI: 10.1302/2058-5241.4.180085.

Early stage periarticular injection during total knee arthroplasty may provide a better postoperative pain relief than late-stage periarticular injection: a randomized-controlled trial

PURPOSE

This study was performed to determine whether periarticular injection performed in the early stage of total knee arthroplasty (TKA) could provide a better postoperative pain relief than periarticular injection performed in the late stage of TKA. The hypothesis was based on the concept that analgesic intervention before the onset of noxious stimuli would be associated with less postoperative pain.

METHODS

A total of 105 participants were randomly assigned to receive superficial injection just prior to arthrotomy (early stage periarticular injection group) or superficial injection after implanting the prosthesis (late-stage periarticular injection group) in patients undergoing unilateral TKA with 1:1 treatment allocation. In both groups, deep injection was performed according to the same schedule (just prior to implanting prosthesis). The solution consisted of 300 mg of ropivacaine, 8 mg of morphine, 40 mg of methylprednisolone, 50 mg of ketoprofen, and 0.3 mg of epinephrine mixed with normal saline to a final volume of 60 mL. All surgeries were managed under general anesthesia without any regional blocks. Registry-specified primary outcome was postoperative pain score at rest measured at the recovery room using a 100-mm visual analog scale (VAS). The VAS score was compared between two groups and assessed to reach the reported threshold values for the minimal clinically important difference (MCID) of 10 mm for the postoperative VAS score.

RESULTS

The VAS score at the recovery room was significantly lower in the early stage periarticular injection group than the late-stage periarticular injection group (23 ± 25 mm versus 39 ± 34 mm, respectively; 95% confidence interval 4-28 mm; p = 0.0078). The mean difference in the primary outcome fulfilled the MCID value.

CONCLUSIONS

Bringing forward the timing of periarticular injection may provide significant and clinically meaningful improvement in pain following TKA under general anesthesia.

LEVEL OF EVIDENCE

I.