Scoring systems in total knee arthroplasty

Unloader brace or high tibial osteotomy in the treatment of the young patient with medial knee osteoarthritis: a randomized controlled trial

BACKGROUND AND PURPOSE

 For medial knee osteoarthritis (OA), operative and nonoperative treatment options are available. Two widely applied unloading therapies are a valgus unloader brace and a high tibial osteotomy (HTO). We aimed to compare the effects of a valgus unloader knee brace with an HTO on knee pain after 1 year in patients with symptomatic medial knee OA.

METHODS

We recruited patients from 9 Dutch hospitals between August 2014 and February 2019 for an open-labeled multi-center randomized controlled trial (Dutch Trial Register NL4200). Patients aged 18 to 65 years with symptomatic medial compartmental knee OA were randomized to either a valgus unloader brace or an HTO. The primary outcome was the pain subscale of the Knee injury and Osteoarthritis Outcome score (KOOS) after 1 year. Patients were evaluated at 3, 6, 9, 12, and 24 months.

RESULTS

 51 patients were included in the study, of whom 23 were randomized to the unloader brace and 28 to the HTO. The HTO, compared with the unloader brace, showed a significant and clinically relevant difference at 12 months of follow-up in KOOS pain of -28 (95% confidence interval -43 to -13).

CONCLUSION

 We found that, on group level, an HTO is more effective in reducing knee pain than an unloader brace after 12 months.

Does previous total hip arthroplasty affect the outcomes of total knee arthroplasty? A one- and five-year follow-up registry study in a monocentric hospital

BACKGROUND

Osteoarthritis in the lower extremities becomes more common as people age. In addition to conservative treatments, hip or knee arthroplasty is often needed. The aim of this study was to evaluate total knee arthroplasty (later TKA) in patients, comparing those who had previously undergone THA (later THA/TKA), with those who had not undergone such procedure. Pain, walking ability and functional capacity were assessed.

METHODS

Patients who underwent primary TKA between 1987 and 2017 at a single orthopaedic hospital was included in this study. The patients participated in clinical preoperative and postoperative examinations by an orthopaedic surgeon after one- and five- years. The final study group consisted of 418 patients who had undergone 502 knee arthroplasties. Of these 502 TKA cases, 462 had not undergone previous THA and 40 had undergone previous THA. To evaluate the patients' physical function and walking ability, a structure form for knee arthroplasty based on the Hungerford score was used. The registry data from the Finnish National Institute of Health and Welfare was used. The data included TKA revision(s) and mortality events.

RESULTS

At the baseline and after one- and five- years primary TKA, no statistical differences were found in the total Hungerford score between TKA patients and THA/TKA patients. In both groups, the total score increased per surgery year. However, when analysing the relationship between the year of operation and the total score, no statistical differences were found between the groups (TKA and THA/TKA) at five years (p = 0.61). The only statistical difference found between the groups was in walking distance points after one year; THA/TKA patients (mean 83 [SD 17]) could walk remarkably shorter distances than TKA patients (91 [14]) one year after arthroplasty (p < 0.001).

CONCLUSIONS

In conclusion, walking distance improved more rapidly in TKA patients than in THA/TKA patients. However, patients who underwent more than one arthroplasty in their lower extremities managed their lives, activities, and pain almost as well as those who underwent only one knee arthroplasty.

Comparative analysis of gait: Similar coronal but different sagittal effects between closing-wedge and opening-wedge high tibial osteotomy

BACKGROUND

High tibial osteotomy is an established surgical option for medial compartment osteoarthritis of the knee with varus alignment. It can be divided into open wedge and closing wedge by operative technique. Although they have fundamental differences, little is known about the biomechanical consequences of the two surgical methods.

METHODS

Thirty-eight patients with medial compartment osteoarthritis who underwent high tibial osteotomy (19 open-wedge and 19 closing-wedge) were retrospectively reviewed. Clinical scores and radiological measurements were assessed until postoperative two years. Gait analysis was performed preoperatively and again at postoperative one year.

FINDINGS

Varus alignment was corrected in both groups without a significant difference between them (p = 0.543). However, posterior tibial slope was higher, and the Blackburne-Peel ratio was lower in the open wedge osteotomy group after surgery (both p < 0.001). Reduction of dynamic knee varus and knee adduction moment were observed in both groups without significant differences. However, after surgery, average knee range of motion (63.3° vs 57.3°, p < 0.001) and the magnitude of knee flexion moment was significantly lower (p = 0.005) in the closing wedge group. There were no significant differences in the Kujala Anterior Knee Pain Scale and the occurrence of patellofemoral arthritis between the groups postoperatively.

INTERPRETATION

After osteotomy, a smaller average knee range of motion in the sagittal plane and a higher knee flexion moment were observed in the open wedge osteotomy group, suggesting quadriceps muscle avoidance. However, no differences in clinical scores or the short-term occurrence of patellofemoral arthritis were noted between the two surgical techniques.

One-Stage Tricompartmental Hypoallergenic UKA for Tricompartmental Osteoarthritis: A Case Report

Osteoarthritis (OA) is a degenerative and progressive joint disease. When all three compartments are involved, end-stage OA is treated with a total knee arthroplasty (TKA). Unicompartmental knee arthroplasty (UKA) is a primary treatment for isolated osteoarthritis. UKA has a quicker recovery time than TKA, as well as less morbidity and more tissue sparing. At the time of surgery, 17% of patients have a tricompartmental disease and most patients with a Kellegren-Lawrence grade >3 have an intact anterior cruciate ligament (ACL). Conventional TKA sacrifices the ACL. Patients with concurrent medial and lateral osteoarthritis and a functional ACL may receive a primary bi-unicondylar arthroplasty. Combined partial knee arthroplasty (CPKA) is an established practice either in bicompartmental femoro-tibial OA or in OA progression after UKA, with the addition of another UKA. A conversion of a lateral UKA to a tricompartmental joint replacement has been reported in the literature. In our case report, we describe a one-stage hypoallergenic tricompartmental UKA, with improved clinical score and no sign of early failure at the last follow-up.

Comparison of accuracy for hip-knee-ankle (HKA) angle by X-ray and knee motion analysis system and the relationships between HKA and gait posture

BACKGROUND

The lower limb mechanical axis was used to assess the severity of knee osteoarthritis (KOA) with varus/valgus deformity and the accuracy of targeted lower limb alignment correction after operation by conventional X-rays. There are lots of parameters to assess the gait in elder patients such as velocity, stride length, step width and swing/stance ratio by knee joint movement analysis system. However, the correlation between the lower limb mechanical axis and gait parameters is not clear. This study is aimed at obtaining the accuracy of the lower limb mechanical axis by the knee joint movement analysis system and the correlation between the lower limb mechanical axis and gait parameters.

METHODS

We analysed 3D knee kinematics during ground gait of 99 patients with KOA and 80 patients 6 months after the operations with the vivo infrared navigation 3D portable knee joint movement analysis system (Opti-Knee®, Innomotion Inc, Shanghai, China). The HKA (Hip-Knee-Ankle) value was calculated and compared to X-ray findings.

RESULTS

HKA absolute variation after the operation was 0.83 ± 3.76°, which is lower than that before the operation (5.41 ± 6.20°, p = 0.001) and also lower than the entire cohort (3.36 ± 5.72). Throughout the cohort, a significant correlation with low coefficients (r = -0.19, p = 0.01) between HKA value and anterior-posterior displacement was found. In comparing the HKA values measured on the full-length alignment radiographs and 3D knee joint movement analysis system (Opti-Knee), there was a significant correlation with moderate to high coefficients (r = 0.784 to 0.976). The linear correlation analysis showed that there was a significant correlation between the values of HKA measured by X-ray and movement analysis system (R² = 0.90, p < 0.01).

CONCLUSIONS

Data with equivalent results as HKA, the 6DOF of the knee and ground gait data could be provided by infrared navigation based 3D portable knee joint movement analysis system comparing with the conventional X-rays. There is no significant effect of HKA on the kinematics of the partial knee joint.

Short-term outcome of total knee replacement in a patient with hemophilia: A case report and review of literature

BACKGROUND

Hemophilia A is a rare inherited bleeding disorder caused by mutations in the factor VIII gene. This clotting factor plays an intrinsic role in the blood coagulation pathway. Patients with hemophilia may develop orthopedic manifestations such as hemarthrosis, but multiple malunion of fractures over the knee is rare and difficult to treat.

CASE SUMMARY

We report a patient with hemophilia A who developed severe knee osteoarthritis along with fracture malunion and nonunion. Total knee replacement was performed using a custom-made modular hinged knee prosthesis (cemented) equipped with extended distal and proximal stems. At 3 years’ follow-up, the patient exhibited excellent clinical function and remained satisfied with the surgical outcome. Surgical intervention was accompanied by rigorous coagulation factor replacement.

CONCLUSION

This case highlights various unique scenarios specific to individuals with hemophilia and fracture deformity.

A scoping review of the outcome reporting following surgery for chronic osteomyelitis of the lower limb

Chronic osteomyelitis (COM) of the lower limb in adults can be surgically managed by either limb reconstruction or amputation. This scoping review aims to map the outcomes used in studies surgically managing COM in order to aid future development of a core outcome set. A total of 11 databases were searched. A subset of studies published between 1 October 2020 and 1 January 2011 from a larger review mapping research on limb reconstruction and limb amputation for the management of lower limb COM were eligible. All outcomes were extracted and recorded verbatim. Outcomes were grouped and categorized as per the revised Williamson and Clarke taxonomy. A total of 3,303 records were screened, of which 99 studies were included. Most studies were case series (77/99; 78%) and assessed one method of reconstruction (68/99; 69%). A total of 511 outcomes were reported, which were grouped into 58 distinct outcomes. Overall, 143/511 of all outcomes (28%) were provided with a clear, in-text definition, and 231 outcomes (45%) had details reported of how and when they were measured. The most commonly reported outcome was 'recurrence of osteomyelitis' (62; 12%). The single-most patient-reported outcome measure was 'pain'. This study has highlighted significant inconsistencies in the defining, reporting, and measuring of outcomes across studies investigating surgical management for chronic osteomyelitis of the lower limb in adults. Future studies should clearly report complete details of how outcomes are defined and measured, including timing. The development of a standardized core outcome set would be of significant benefit in order to allow evidence synthesis and comparison across studies.

Is sequential bilateral robotic total knee arthroplasty a safe procedure? A matched comparative pilot study

INTRODUCTION

To our knowledge, no papers have reported the results of robotic-assisted surgery for sequential bilateral Total Knee Arthroplasty (TKA). Indeed, sequential bilateral TKA present several benefits, as one single anesthesia, surgical episode, hospitalization, and rehabilitation. The purpose of our study was to evaluate peri-operative outcomes and compare the complication rates, clinical outcomes, and implant positioning of sequential bilateral TKA performed with a robotic-assisted system versus a conventional technique.

MATERIALS AND METHODS

All patients who underwent a sequential bilateral robotic-assisted primary TKA (raTKA) in our institution between November 2019 and February 2021 were included. Twenty patients met the inclusion criteria and were matched with 20 sequential bilateral TKA performed with a conventional technique. The two groups were comparable for the demographic data and the preoperative parameters, including preoperative anticoagulation and ASA score. The minimum follow-up was 6 months.

RESULTS

The operative time was significantly longer in the robotic group (< 0.0001), with a mean additional time of 29 min. There was no significant difference between both groups for postoperative blood loss, rate of blood transfusion, or postoperative pain. The average length of stay was 5 days. There was one early complication in the robotic group due to the tibial trackers. The functional outcomes were similar between both groups, except for the functional KSS score, which was better at 6 months in the robotic group (p < 0.0001). The restoration of the knee alignment and the distal femoral anatomy were significantly better in the robotic group than in the conventional group.

CONCLUSIONS

Despite a longer operative time, the peri-operative parameters of sequential bilateral TKA were similar between robotic and conventional techniques. Further, sequential bilateral raTKA was at least as safe as a conventional technique, without additional risk of medical complications.

Are soft tissue releases sufficient to correct moderate to severe flexion contractures during total knee replacement? Role of hamstring tenotomy and horizontal capsular release

BACKGROUND

Performing total knee arthroplasty (TKA) in arthritic knees with persistent flexion deformities is a challenging task because secondary tightening of surrounding soft tissues makes it difficult to achieve appropriate ligament balancing. In this study, we shared our algorithm for correction of flexion contractures of moderate to severe grade while performing TKA as well as their outcomes with 1 year of follow up.

METHODS

Forty-three patients (61 knees) having knee arthritis with moderate to severe flexion contractures (Lombardi classification) were included in the study. We followed a stepwise algorithm of soft tissue releases for correction of flexion contracture, which included: removal of posterior osteophytes, release of posterior capsule, gastrocnemius release, horizontal capsular release, and hamstring tenotomy. Patients were followed up at 15 days, 6 weeks, 3 months and 1 year, and assessed clinically for residual flexion deformity (FFD), range of motion (ROM), New Knee Society (New KSS) score and Hospital for Special Surgery (HSS) score.

RESULTS

Pre-operative mean FFD 29.07 ± 18.04 standard deviation (SD) was corrected to 0.77 ± 2.93 SD at 1 year follow up. Pre-operative mean ROM 71.37 ± 22.18 increased to 107.7 ± 10.38 at 1 year follow up. There was statistically significant improvement in mean New KSS score and reduction in number of cases with poor HSS score at 1 year follow up.

CONCLUSIONS

Moderate flexion contractures can be corrected with soft tissue releases without distal femoral over-resection. In severe deformities, horizontal release of posterior capsule and hamstring tenotomy are crucial, and residual contractures of up to 20° can be well corrected by postoperative physiotherapy and extension bracing.

Usefulness of the Kinect-V2 System for Determining the Global Gait Index to Assess Functional Recovery after Total Knee Arthroplasty

OBJECTIVE

The Korean Knee Society (KKS) score is used for functional evaluation during follow-up after total knee arthroplasty (TKA), but it is time-consuming to measure and is limited by its subjective nature. We investigated whether the global gait asymmetry index (GGA) that can be obtained using the Kinect-V2 system could overcome the KKS limitations.

METHODS

Forty-three patients who underwent TKA from January 2019 to December 2019 were included. Postoperatively, regular follow-up was performed at 2, 4, 6, 8, and 12 weeks, and at 4, 6, and 12 months. At each follow-up visit, the KKS was measured, and the walking path was followed with six Kinect-V2 systems. After allowing the participants to walk naturally, the range of motion of each joint of the lower extremity and GGA were obtained. Changes in the KKS and GGA scores and measurement times were investigated until the final follow-up. A statistical model was made to predict the KKS from the GGA score using data at all observed time points, and analysis of variance (ANOVA) with Turkey's post-hoc tests and Pearson correlation tests were used for evaluation.

RESULTS

Both the KKS and GGA scores improved significantly from 4 weeks postoperatively until the final follow-up. The measurement time was significantly shorter for the GGA (9.3 ± 1.4 min) than for the KKS (32.4 ± 9.2 min; P < 0.001) score. The predicted and actual KKS values clustered close to a straight line on the scatter plot, but the prediction was less accurate in the initial stage (2 weeks post-surgery) than at later time points. The mean absolute error (MAE) and root mean square of the error (RMSE) were considered to be poorly predicted in the initial stage (8 weeks post-surgery) compared to the later time-points (MAE ≥ 5 and RMSE ≥ 6 for 8 weeks post-surgery).

CONCLUSION

In the early phase after knee joint surgery (up to 12 weeks post-surgery), the GGA index does not predict the KKS well. However, after this time point, the GGA index can be simply measured in the outpatient department and may be able to replace the KKS. Thus, evaluation of the GGA index using the Kinect-V2 may be a useful method to evaluate functional recovery in the outpatient clinic after knee joint surgery.

An anatomo-functional implant positioning technique with robotic assistance for primary TKA allows the restoration of the native knee alignment and a natural functional ligament pattern, with a faster recovery at 6 months compared to an adjusted mechanical technique

PURPOSE

An anatomo-functional implant positioning (AFIP) technique in total knee arthroplasty (TKA) could restore physiological ligament balance (symmetric gap in extension, asymmetric gap in flexion). The purposes were to compare (1) ligament balancing in extension and flexion after TKA in the AFIP group, (2) TKA alignment, implant positioning and patellar tracking between AFIP and adjusted mechanical alignment (aMA) techniques, (3) clinical outcomes between both groups at 12 months.

METHODS

All robotic-assisted TKA with an AFIP technique were included (n = 40). Exclusion criteria were genu valgum (HKA angle > 183°), extra-articular deformity more than 10°, and patellar maltracking (high-grade J-sign). One control patient with a TKA implanted by an aMA technique was matched for each case, based on age, body mass index, sex, and knee alignment. Ligament balancing (medial and lateral gaps in millimeters) in full extension and at 90° of flexion after TKA in the AFIP group was assessed with the robotic system. TKA alignment (HKA angle), implants positioning (femoral and tibial coronal axis, tibial slope, joint-line orientation), patellar tracking (patellar tilt and translation) and the Knee Society Score (KSS) at 6 and 12 months were compared between both groups. The ligament balancing was compared using a t test for paired samples in the AFIP group. The radiographic measurements and KSS scores were compared between groups using a t test for independent samples.

RESULTS

In the AFIP group, there was no significant difference between the medial and lateral gap laxity in extension (NS). A significant opening of the lateral gap was observed in flexion compared to extension (mean: + 2.9 mm; p < 0.0001). The mean postoperative HKA angle was comparable between both groups (177.3° ± 2.1 in the AFIP group vs 176.8° ± 3.2; NS). In the AFIP group, the femoral anatomy was restored (90.9° ± 1.6) and the tibial varus was partially corrected (87.4° ± 1.8). The improvement of Knee and Function KSS at 6 months was better in the AFIP group (59.3 ± 11.9 and 51.7 ± 20, respectively, versus 49.3 ± 9.7 and 20.8 ± 13; p < 0.001).

CONCLUSION

The AFIP concept allowed the restoration of the native knee alignment and a natural functional ligament pattern. With a more physiological target for ligament balancing, the AFIP technique had equivalent clinical outcomes at 12 months compared to aMA, with a faster recovery.

LEVEL OF EVIDENCE

III retrospective therapeutic case control series.

A validated outcome categorization of the knee society score for total knee arthroplasty

PURPOSE

To determine cutoff values for the Knee Society Scores (KSS) indicative of a categorical scale of medium-term outcomes.

METHODS

One hundred and fifty-five patients who underwent primary cruciate-retaining TKA with a patellar button for osteoarthritis at a single-centre were assessed prospectively by the KSS and short-form Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) simultaneously at the 3-year follow-up. A validated categorization of the WOMAC score was used as a standard. The area under the curve (AUC) of receiver-operating characteristic (ROC) was used to assess the discriminative analysis accuracy of the, and the Youden index estimated the optimal cutoff point.

RESULTS

For the KSS-knee score, the cutoff for an excellent outcome was 90.3 (AUC 0.75, 95% CI 0.71-0.78), 76.6 (AUC 76.6, 95% CI 0.70-076) for good, 64.8 (AUC 0.76, 95% CI 0.72-0.79) for fair, and < 64.8 (AUC 0.69, 95% CI 0.67-0.73) for poor. For the KSS-function score, the cutoff values were 85.2 (AUC 0.71, 95% CI 0.69-0.75), 73.1 (AUC 0.72, 95% CI, 0.70-0.76), 55.7 (AUC 0.70, 95% CI 0.71-0.74), and < 55.7 (AUC 0.68, 95% CI 0.66-0.72), respectively.

CONCLUSION

A KSS-knee score ≥ of 90 was considered an excellent outcome, 77 good, 65 fair, and < 65 poor. For the KSS-function, those values are 85, 73, 56 and < 56, respectively. The treatment outcome's judgement may be clearer for the surgeon concerning a particular patient when using cutoff values for the scoring system employed, such as those determined in the present study.

LEVEL OF EVIDENCE

II.

Fixed bearing, all-polyethylene tibia, lateral unicompartmental arthroplasty - A final outcome study with up to 28 year follow-up of a single implant

BACKGROUND

Lateral unicompartmental arthroplasty (UKA) constitutes only 5-10% of all unicompartmental replacements performed. Whilst the short and medium term benefits are well documented, there remains concern regarding the higher revision rate when compared with total knee replacement. We report the long term clinical outcome and survivorship of a large series of lateral UKA.

PATIENTS AND METHODS

Between 1974 and 1994, 71 patients (82 knees) underwent a lateral fixed-bearing St Georg Sled UKA. Prospective data was collected pre-operatively and at regular intervals post-operatively using the Bristol Knee Score (BKS), with later introduction of the Oxford Knee (OKS) and Western Ontario MacMaster (WOMAC) scores. Kaplan Meier survival analysis was used, with revision, or need for revision, as end point. 85% of the patients were female. No patients were lost to follow-up.

RESULTS

Functional knee scores improved post-operatively up to 10 years, at which point they demonstrated a steady decline. Survivorship was 72% at 15 years, and 68% at 20 and 25 years. Nineteen knees were revised, with progression of disease in another compartment the commonest reason. There were two revisions due to implant fracture. In patients aged over 70 years at time of index procedure, 81% died with a functioning prosthesis in situ.

CONCLUSION

This represents the longest follow-up of a large series of lateral UKA. Results of this early design of fixed bearing UKA demonstrate satisfactory long term survivorship. In elderly patients, further intervention is rarely required. More contemporary designs or techniques may show improved long term survivorship in time.

Association of HSS score and mechanical alignment after primary TKA of patients suffering from constitutional varus knee that caused by combined deformities: a retrospective study

For pre-operative osteoarthritis (OA) patients with varus knee, previous studies showed inconsistent results. Therefore, we conducted this study to better identify the association of Hospital for Special Surgery (HSS) score and mechanical alignment. 44 patients (51 knees) with constitutional varus knee caused by combined deformities (LDFA (lateral distal femoral angle) > 90°and MPTA (medial proximal tibial angle) < 85°)) were selected and analyzed with a mean follow-up period of 14 months after total knee arthroplasty (TKA). From January 2015 to December 2016, patients were collected consecutively after primary TKA. After filtering, fifty-one knees (44patients) were analyzed with a mean follow-up period of 14 months. All patients were divided into two groups based on post-operative hip-knee-ankle (HKA) acute angle: varus mechanical alignment (VMA) group (HKA < - 3°) and neutral mechanical axis (NMA) group (- 3° ≤ HKA ≤ 3°). 30 knees were included in the NMA group, and 21 knees in the VMA group. Comparisons of HSS between NMA group and VMA group were performed. After adjusting for age and Body Mass Index (BMI) confounders, Compared with NMA group, the HSS score in VMA group decreased by 0.81 units (95% CI, - 3.37 to 1.75) p = 0.5370). For pre-operative constitutional varus knee caused by combined deformities in chinese populations, no significant association between post-operative lower limb mechanical alignment and HSS score was found.

Application of enhanced recovery after surgery in total knee arthroplasty in patients with haemophilia A: A pilot study

Aim

To identify the effect of enhanced recovery after surgery (ERAS) and rapid rehabilitation concepts on the outcomes of patients with haemophilia A undergoing total knee arthroplasty.

Design

Randomized controlled trial.

Methods

The primary endpoint was postoperative hospital stay. The secondary endpoints were pain scores, joint function scores, haemoglobin levels at 3 and 7 days after surgery and satisfaction with hospitalization.

Results

Thirty-two patients were enrolled. Compared with the routine nursing group, the ERAS group showed shorter postoperative hospital stay (14.2 SD 0.8 vs. 16.6 ± 1.3 days, p < .001), smaller amounts of blood transfusion (924 SD 317 vs. 1,263 SD 449 ml, p = .020) and coagulation factors (37,325 SD 5,996 vs. 48,475 SD 8,019 U, p < .001), lower pain scores at 3 (3.3 SD 0.7 vs. 4.3 SD 0.7, p = .002) and 7 (2.3 SD 0.7 vs. 2.8 ± 0.5, p = .015) days, lower hospital for special surgery knee scores at 3 (59.9 SD 7.8 vs. 53.6 SD 5.9, p = .016) and 7 (77.9 SD 6.9 vs. 71.1 ± 7.1, p = .009) days and higher satisfaction with hospitalization (94.3 SD 1.4 vs. 92.7 SD 1.6, p = .004).

The Effect of Time Spent with a Dynamic Spacer on Clinical and Functional Outcomes in Two-Stage Revision Knee Arthroplasty

INTRODUCTION

The present study aimed to evaluate the effect of a longer interval between the first and second stages of infected total knee arthroplasty (TKA) revision on the clinical and functional outcome.

METHODS

This study included a total of 56 patients who underwent two-stage revision TKA with a dynamic spacer with a minimum of 2 years of follow-up. Patients were categorized into two groups according to time with the spacer: < 3 months (Group 1, 31 patients) or > 3 months (Group 2, 25 patients). Clinical outcome and quality of life were assessed by knee range of motion (ROM), Knee Society Score for Knee (KSS-K), Knee Society Score for Function (KSS-F) and Short Form 36 (SF-36).

RESULTS

The mean follow-up period was 48 ± 19.1 months (range, 24-84 months). The KSS-K, KSS-F, and ROM values were significantly higher in Group 1 than in Group 2 (p < 0.05). The SF-36 scores for general health, physical function, and bodily pain were significantly higher in Group 1 (p < 0.05). Re-infection occurred in 10 patients (17.8%). Time with spacer was not associated with re-infection development (Group 1, n = 6, 19% vs. Group 2, n = 4, 16%; p > 0.05).

CONCLUSION

Increased duration with a spacer is associated with poorer clinical and functional outcomes as well as higher treatment costs in two-stage revision knee arthroplasty. Surgeons can attempt to reduce the time patients spend in a spacer to obtain better postoperative functional outcomes, as well as a better quality of life.

LEVEL OF EVIDENCE

3.

Using electroacupuncture to recover muscle strength in patients with knee osteoarthritis after total knee arthroplasty: a study protocol for a double-blinded, randomized, and placebo-controlled trial

BACKGROUND

Total knee arthroplasty (TKA) is a gold standard for patients with terminal term gonarthrosis for reducing pain, correcting deformities, and regaining stability. However, post-TKA muscle strength recovery is often difficult. Although electroacupuncture (EA) enhances lower extremity muscle strength of the lower extremity, there is limited evidence regarding its effect on lower extremity muscle strength in post-TKA patients. Consequently, this trial intends to evaluate the efficacy of post-TKA EA on the recovery of lower extremity muscle strength, specifically, during the early post-TKA period.

METHODS/DESIGN

This is a double-blinded, randomized, and controlled trial. It will be conducted between August 2020 and December 2020. Ninety-four participants with KOA who have undergone unilateral TKA will be randomized into a treatment (EA) group and a control (sham EA) group. The former and latter groups will receive EA and sham EA, respectively, at ST37, ST36, SP10, and SP9 acupoints. The participants will undergo ten treatment sessions over 2 weeks (5 sessions per week). The primary outcomes will include changes in muscle strength and the Hospital for Special Surgery score at the second week from baseline (pre-op 1 day or POD 3). The secondary outcomes will include a 4-m walk test, numerical rating scale score, the Hamilton Anxiety Scale score, and additional analgesia use. Additional outcomes will include the incidence of analgesia-related side effects and the participant satisfaction rate. Participant blinding will also be assessed where they will be asked to guess whether they received EA after the latest intervention. Adverse EA events will be documented and assessed throughout the trial.

DISCUSSION

EA is helpful for post-TKA recovery and enhancement of lower limb muscle strength.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR1900027806 . Registered on 29 November 2019.

Functional recovery after two-stage short-interval revision of chronic periprosthetic knee joint infection

PURPOSE

The objective of this study was the functional recovery analysis of patients treated in two-staged short-interval procedure due to knee periprosthetic joint infection (PJI).

MATERIALS AND METHODS

In the period from January 2015 to December 2018, a two-stage short-interval revision TKA was performed in 35 patients with PJI. Synovial fluid analysis, tissue samples and sonication method were used to diagnose PJI. Active range of motion (AROM) and Hospital for Special Surgery (HSS) score were analysed.

RESULTS

Functional recovery analysis demonstrated higher AROM and HSS score after the revision TKA. Median pre-operative active flexion motion was 80° with full active extension, and median post-operative active flexion was 105° with full active extension. Median HSS score pre-operatively was 22 and post-operatively was 48. Isolated bacteria in both tissue and sonication fluid were S. epidermidis (27%) and other coagulase-negative staphylococci (25%), followed by S. aureus (10%).

CONCLUSION

Two-stage short-interval procedure of chronic knee PJI significantly improved functional status of patients in a short period of time. Thirty three out of 35 patients returned to their everyday activities. Adequate surgical technique and implant selection can lead to satisfactory functional outcome.

Comparison of cannulated lag screws and lateral locking plate in the treatment of Schatzker type II tibial plateau fractures

Objectives

This study aims to compare the clinical and radiological outcomes of the two fixation methods frequently used in the treatment of Schatzker type II fractures: lag screw fixation and lateral anatomic plate fixation.

Patients and methods

This retrospective study, which was conducted between January 2005 and December 2014, included 61 patients (41 males, 20 females; mean age 43.4±13.1 years; range, 20 to 76 years) with Schatzker type II (Orthopaedic Trauma Association (OTA)/Arbeitsgemeinschaft für Osteosynthesefragen (AO) 41-B3) fractures. Patients were divided into two groups according to the type of surgery as cannulated lag screw fixation group (group 1, n=24, 39.4%) and lateral locking plate fixation group (group 2, n=37, 60.6%). Intraoperative mediolateral and anteroposterior instability were measured. Final knee flexion- extention range of motion (ROM), single-leg hop test, Knee Society Score (KSS), Hospital for Special Surgery (HSS) and short form 36 (SF36) scores were obtained at the last follow-up.

Results

The mean age of patients was 42.1±13.8 years in group 2 and 45.5±12.2 years in group 1. The mean follow-up period was 34±4 months. Minimal or no arthritis was detected in 75% (n=18) of patients in group 1 and 78% (n=29) of patients in group 2 (p=0.27). Single leg-hop test results (p=0.55), final follow-up knee ROM (p=0.40), KSS (p=0.21), HSS (p=0.15), and SF36 scores of group 1 were similar to group 2. In group 1, the duration of surgery was shorter (p<0.001) and the cost of treatment was lower (p<0.001).

Conclusion

Treatment of Schatzker type II tibial plateau fractures with lag screws seems to provide less invasive, cheaper, and faster surgical treatment as compared with lateral locking plate fixation. In addition, patients who underwent internal fixation with lag screws had similar clinical and radiological outcomes with those who underwent lateral locking plate fixation.

The Relationship between Knee Adduction Moment and Knee Osteoarthritis Symptoms according to Static Alignment and Pelvic Drop

Objectives

To investigate the relationship between external knee adduction moment (KAM) and knee osteoarthritis (OA) symptoms according to static alignment and pelvic drop.

Methods

Ninety-five participants with symptomatic knee OA were included. Radiographic severity was graded by Kellgren and Lawrence (KL) scale. The hip-knee-ankle (HKA) angle was used to assess limb alignment from a full-length lower-limb radiograph. KAM-related variables (peak KAM and KAM impulse) and pelvic drop angle were determined from 3D gait analysis. Symptoms were assessed via visual analog scale (VAS) for pain and hospital for special surgery (HSS) score for physical function. The relationship between KAM and symptoms was evaluated according to radiographic severity and pelvic drop using linear models.

Results

According to the more affected knee in the varus group, both the two KAM-related measures (peak KAM and KAM impulse) were positively associated with greater VAS pain and were negatively associated with HSS score. Only peak KAM was correlated with VAS and HSS in the valgus group. VAS pain score of the more affected knee was positively correlated with pelvic drop angle. Stratified by pelvic drop angle, KAM-related variables were more positively associated with VAS pain and negatively associated with HSS score for patients with pelvic drop angle ≤3 degrees. The relationships between KAM and symptoms according to radiographic disease severity remained confusing.

Conclusions

Static alignment and pelvic drop angle significantly affected relationships between KAM-related variables and knee OA symptoms, which may explain the confusing results as shown by previous studies.

Application of electroacupuncture for postoperative pain management after total knee arthroplasty: a study protocol for a single-blinded, randomised placebo-controlled trial

INTRODUCTION

The purpose of this study is to assess the efficacy of electroacupuncture (EA) to relieve pain and promote functional rehabilitation after total knee surgery.

METHODS AND ANALYSIS

We propose a single-blinded, randomised placebo-controlled trial to evaluate the efficacy of EA. Patients with osteoarthritis (aged 55-80 years) undergoing unilateral total knee arthroplasty (TKA) will be included in the trial. They will be randomised to receive either EA or sham-EA. A total of 110 patients will receive EA and sham-EA for 3 days after TKA. Postoperative pain will be measured using visual analogue score, and the need for an additional dose of opioid and analgesics will be recorded as the primary outcome. Secondary outcomes include knee function and swelling, postoperative anxiety, postoperative nausea and vomiting among other complications.

ETHICS AND DISSEMINATION

This study has been approved by the ethics committee, and subsequent modifications of the protocol will be reported and approved by it. Written informed consent will be obtained from all of the participants or their authorised agents.

TRIAL REGISTRATION NUMBER

ChiCTR1800016200; Pre-results.

A 13- to 16-year clinical and radiological outcome study of the genesis II cruciate retaining total knee arthroplasty with an oxidised zirconium femoral component

PURPOSE

The Genesis II Total Knee Arthroplasty with an oxidized zirconium (OxiniumTM) femoral component (Smith & Nephew, Memphis, TN, USA) was introduced in an attempt to reduce polyethylene wear and osteolysis.

METHODS

We retrospectively evaluated prospectively collected data from 245 consecutive patients (40 men and 205 women; mean age at surgery 70.1 years, range 44 to 85 years) who underwent 261 TKAs with a mean follow-up of 15.1 years (range 13 to 16 years). Implant failure rate, complication rate, clinical (both subjective and objective) and radiological outcomes were assessed.

RESULTS

At final follow-up, 24 (9.8 %) patients (24 TKAs) were lost to follow-up and 35 (14.3%) patients (35 TKAs) had died for reasons unrelated to surgery. Four TKAs, in four patients, were revised because of aseptic loosening. In five TKAs (five patients) secondary patella resurfacing was performed because of patellofemoral pain. Survivorship analysis showed a cumulative success rate of 98.4% (95% CI, 94.3% - 100%) at 15 years with revision for aseptic loosening as an end point, and 95.6% (95% CI, 92.7% - 98.7%) at 15 years with revision for any reason as an end point. All patients showed a statistically significant improvement (p = 0.01) in the Knee Society clinical rating system, WOMAC Score, KOOS Score, Oxford Knee Score and EuroQol 5D Score. Surgery fulfilled patient expectations for 90.1% of patients; in 5.4% it did not, and 4.5% declined to answer.

CONCLUSION

This study demonstrates satisfactory long-term clinical results for this knee design.

Robotic-assisted total knee arthroplasty may lead to improvement in quality-of-life measures: a 2-year follow-up of a prospective randomized trial

PURPOSE

Despite reduction in radiological outliers in previous randomized trials comparing robotic-assisted versus conventional total knee arthroplasty (TKA), no differences in short-term functional outcomes were observed. The aim of this study was to determine whether there was improvement in functional outcomes and quality-of-life (QoL) measures between robotic-assisted and conventional TKA.

METHODS

All 60 knees (31 robotic-assisted; 29 conventional) from a previous randomized trial were available for analysis. Differences in range of motion, Knee Society (KSS) knee and function scores, Oxford Knee scores (OKS), SF-36 subscale and summative (physical PCS/mental component scores MCS) were analysed. In addition, patient satisfaction, fulfilment of expectations and the proportion attaining a minimum clinically important difference (MCID) in KSS, OKS and SF-36 were studied.

RESULTS

Both robotic-assisted and conventional TKA displayed significant improvements in majority of the functional outcome scores at 2 years. Despite having a higher rate of complications, the robotic-assisted group displayed a trend towards higher scores in SF-36 QoL measures, with significant differences in SF-36 vitality (p = 0.03), role emotional (p = 0.02) and a larger proportion of patients achieving SF-36 vitality MCID (48.4 vs 13.8 %, p = 0.009). No significant differences in KSS, OKS or satisfaction/expectation rates were noted.

CONCLUSION

Subtle improvements in patient QoL measures were observed in robotic-assisted TKA when compared to conventional TKA. This finding suggests that QoL measures may be more sensitive and clinically important than surgeon-driven objective scores in detecting subtle functional improvements in robotic-assisted TKA patients.

LEVEL OF EVIDENCE

II.

Clinical Evaluation and Gait Characteristics before and after Total Knee Arthroplasty Based on a Portable Gait Analyzer

OBJECTIVE

To evaluate the effects of surgery and rehabilitation on patients undergoing total knee arthroplasty (TKA).

METHODS

Twelve patients and 12 healthy controls were enrolled and their clinical scores evaluated by a doctor. Gait data, including walking velocity, stride length, single support time, foot fall and swing power, were collected using a portable gait analyzer from 12 patients before and 6 weeks and 6 months after surgery and from 12 healthy controls. The gait data and clinical scores at selected time points were compared and correlations between gait characteristics and clinical scores assessed.

RESULTS

Clinical knee and knee function scores increased significantly from before surgery to 6 weeks to 6 months after surgery (P < 0.001). The only significant differences identified were for single support time on the diseased side between before surgery and 6 months after surgery (P = 0.031) and for foot fall with the diseased side between 6 weeks and 6 months after surgery (P = 0.016). Foot fall and speed of the healthy or diseased sides were significantly different in patients at all time points from those of the healthy subjects (P < 0.05). Single support time on the diseased side was significantly different 6 months after surgery (P = 0.035) in patients than in healthy controls. Single support time on the healthy side before surgery was significantly different from that of healthy controls (P = 0.048) and 6 weeks after surgery (P = 0.042). Stride lengths differed significantly between patients and healthy subjects before surgery (healthy side: P = 0.007; diseased side: P = 0.008) and 6 weeks after surgery (healthy side: P = 0.001; diseased side: P = 0.001), but were not different at 6 months after surgery (healthy side: P = 0.088; diseased side: P = 0.077). The only significant correlations identified were between single support time with the diseased side of patients and their knee (r = 0.43, P = 0.032) and knee function scores (r = 0.493, P = 0.012).

CONCLUSIONS

A portable gait analyzer appears to be suitable for evaluating the effects of TKA. Single support time on the diseased side may be a sensitive quantitative index for determining the effect of TKA and rehabilitation.

The Use of Scoring Systems in Knee Arthroplasty: A Systematic Review of the Literature

BACKGROUND

The primary purpose of this systematic review was to clarify and quantify scoring system utilization in knee arthroplasty literature. In addition, the study considered the frequency and relationship of score use in articles published across a range of orthopedic journals, and the influence of study design, level of evidence, primary research topic, and study country of origin on the scoring system used.

METHODS

A systematic search of 8 electronic databases was performed to identify publications of clinical studies involving knee arthroplasty, in which a scoring system was used to assess patient outcomes.

RESULTS

Of the 1994 unique publications identified, 438 met the selection criteria. Identified articles reported a total of 86 scoring systems, 5 of which were reported in greater than 10.0% of included studies. The 1989 Knee Society Score was markedly the most utilized scoring system (58.7%). Use of the Knee Society Score was significantly associated with orthopedic journal impact factor (IF; P = .001), with greater use observed in journals of lower IF. Use of the Western Ontario and McMaster Universities Osteoarthritis Index escalated with increasing IF; however, no statistically significant association was observed. A preference for scoring systems developed in the country of residence of the first author was also identified.

CONCLUSIONS

A large number of scoring systems are used to assess knee arthroplasty patients; however, 5 scores are consistently reported. By identifying and quantifying scoring system use, this review hopes to stimulate regularity in score usage to allow for improvements in comparability of clinician and patient-reported outcome measures in the knee arthroplasty literature.

Physiotherapy-led arthroplasty review clinic: a preliminary outcomes analysis

OBJECTIVE

With the rising demand for Orthopaedics in the healthcare sector, service delivery innovations need to be explored to accommodate the increasing workload. Senior Musculoskeletal Physiotherapists have the specialised skills in the assessment of musculoskeletal conditions to determine the impact of surgery on patient outcomes. The aim of the present study was to compare outcomes between a physiotherapy-led arthroplasty review clinic (PT clinic) and the traditional model of orthopaedic surgeon review (OS clinic) after hip and knee replacement.

METHODS

This study was a retrospective case-controlled audit using a comprehensive database. Twenty-four patients who had a hip arthroplasty and 52 patients who had a knee arthroplasty were reviewed solely by the PT clinic at 3, 6 and 12 months after surgical reviews. These patients were matched 1:2 against patients seen only by the OS clinic. The outcome measures included International Knee Score (IKS), Harris Hip Score (HHS) and the Short Form (SF)-12.

RESULTS

There were no significant differences in HHS or SF-12 scores for patients after hip arthroplasty. Significant differences for knee arthroplasty were observed favouring the PT clinic; IKS, PT clinic 147.6 (37.07), OS clinic 135.4 (35.68), P≤0.01, and physical component of the SF-12, PT clinic 41.98 (10.45), OS clinic 37.20 (10.44), P<0.01.

CONCLUSION

Implementation of a physiotherapy-led arthroplasty review clinic appears to be a safe and effective service alternative to reviews conducted by orthopaedic surgeons. WHAT IS KNOWN ABOUT THE TOPIC?: Osteoarthritis (OA) is a leading cause of musculoskeletal pain and disability and the burden of the disease is rapidly increasing. Joint arthroplasty surgery is the mainstay of treatment for people with end-stage OA; it is a high-cost, high-volume procedure that dominates surgical wait lists around Australia. Long-term follow up is encouraged by the Arthroplasty Society of Australia and endorsed by the Australian Orthopaedics Association, but it is acknowledged that it is impossible to achieve this with solely orthopaedic surgeon reviews, an issue that is only going to worsen with the increased demand for surgery. Physiotherapists have become involved in many advanced scope roles within public health care, and emerging research suggests that patients are highly satisfied with their care in these types of clinics. WHAT DOES THIS PAPER ADD?: Although it has been shown that patients are satisfied in physiotherapy-led advanced clinics, there is a paucity of evidence in the outcomes of patients attending these clinics. Implementation of a physiotherapy-led arthroplasty review clinic demonstrated that outcome measures in this patient cohort were not compromised and, following knee joint arthroplasty, may even be improved. WHAT ARE THE IMPLICATIONS FOR PRACTITIONERS?: The findings of this study indicate that joint review clinics involving physiotherapists acting in an advanced scope role are unlikely to compromise patient outcomes. The use of this role substitution on a broader scale can be recommended.

Conversion of a Surgically Arthrodesed Knee to a Total Knee Arthroplasty-Is it Worth it? A Meta-Analysis

BACKGROUND

Conversion of a surgically arthrodesed knee to total knee arthroplasty (TKA) is an option for a select group of patients who are not satisfied with their results. However, there is a paucity of literature on this topic. A systematic review of literature was performed to (1) describe the overall demographic characteristics; (2) evaluate the clinical outcomes; (3) determine the overall rate of complications; and (4) evaluate the overall satisfaction of patients who underwent conversion of an arthrodesed knee to TKA.

METHODS

A comprehensive literature search was systematically performed to evaluate all studies included in the literature until July 2015. The specific search terms used were "fusion knee" and "arthrodesis knee," which revealed a total of 2206 studies. A review and selection of these abstracts were then performed based on inclusion and/or exclusion criteria; a total of 10 articles were used for final review.

RESULTS

There were a total of 98 surgically arthrodesed knees that subsequently underwent TKA. Patients had a mean age of 55 years and were followed up for a mean of 5 years. Using a random effects model, there was an overall complication rate of 47%, an overall revision rate of 25%, and an overall failure rate of 11%. However, most patients were overall satisfied with the procedure.

CONCLUSION

Fusion takedown is a challenging procedure that should only be performed by experienced surgeons after extensive discussion with the patients. The clinical outcomes are good with overall patient satisfaction, but complication rates are high including risk of repeat fusion or amputation.

10-Year Survival of Navigated Versus Conventional TKAs: A Retrospective Study

The computer-assisted navigation of total knee arthroplasty (TKA) offers a radiologically demonstrated higher precision of implantation than conventional implantation in relation to the axis alignment. The impact on long-term clinical outcomes is currently unknown. In 1999, 217 consecutive TKAs were performed in a total of 213 patients (113 navigated and 104 conventional). After 10 years, it was possible to follow up on 94 patients with 96 TKAs, of which 46 were conventional and 50 were navigated. The radiographs were evaluated using the Knee Society protocol. In addition to the Hospital for Special Surgery Score and Knee Society Score, the current authors also used the patient-focused 36-item Short Form Health Survery. After 10 years, 8 TKAs were revised because of aseptic loosening, 7 in the conventional group and 1 in navigated group. This equates to an 87% survival rate for conventional and 98% for navigated implantation. This difference was statistically significant (P<.05). After conclusion of the follow-up, 17% of the conventional and 9.8% of the navigated TKAs were found to have undergone aseptic loosening. All of the TKAs subject to aseptic loosening presented a mechanical femorotibial angle outside the optimal zone of ±3° around neutral axis. The study indicates a clinically significant advantage of the navigation technique compared with the conventional procedure. [Orthopedics. 2016; 39(3):S72-S76.].

Alignment of the lower extremity mechanical axis by computer-aided design and application in total knee arthroplasty

PURPOSE

The success of total knee arthroplasty (TKA) depends on many factors. The position of a prosthesis is vitally important. The purpose of the present study was to evaluate the value of a computer-aided establishing lower extremity mechanical axis in TKA using digital technology.

METHODS

A total of 36 cases of patients with TKA were randomly divided into the computer-aided design of navigation template group (NT) and conventional intramedullary positioning group (CIP). Three-dimensional (3D) CT scanning images of the hip, knee, and ankle were obtained in NT group. X-ray images and CT scans were transferred into the 3D reconstruction software. A 3D bone model of the hip, knee, ankle, as well as the modified loading, was reconstructed and saved in a stereolithographic format. In the 3D reconstruction model, the mechanical axis of the lower limb was determined, and the navigational templates produced an accurate model using a rapid prototyping technique. The THA in CIP group was performed according to a routine operation. CT scans were performed postoperatively to evaluate the accuracy of the two TKA methods.

RESULTS

The averaged operative time of the NT group procedures was [Formula: see text] min shorter than those of the conventional procedures ([Formula: see text]  min). The coronal femoral angle, coronal tibial angle, posterior tibial slope were [Formula: see text], [Formula: see text], [Formula: see text] in NT group and [Formula: see text], [Formula: see text], [Formula: see text] in CIP group, respectively. Statistically significant group differences were found.

CONCLUSIONS

The navigation template produced through mechanical axis of lower extremity may provide a relative accurate and simple method for TKA.

Latent Class Growth Analysis predicts long term pain and function trajectories in total knee arthroplasty: a study of 689 patients

OBJECTIVE

To characterize groups of subjects according to their trajectory of knee pain and function over 1 to 5 years post total knee arthroplasty (TKA).

METHODS

Patients from one centre who underwent primary TKA (N = 689) between 2006 and 2008. The Knee Society Score (KSS) was collected pre-operatively and annually post-operatively. Latent Class Growth Analysis (LCGA) was used to classify groups of subjects according to their trajectory of knee pain and function over 1-5 years post-surgery.

RESULTS

LCGA identified a class of patients with persistent moderate knee pain (22.0%). Predictors (OR, 95% CI) of moderate pain trajectory class membership were pre-surgery SF12 mental component summary (MCS) per 10 points (0.65, 0.54-0.79) and physical component summary (PCS) per 10 points (0.50, 0.33-0.76), Charlson Comorbidity Index (CCI) one (1.70, 1.07-2.69) and ≥two (2.82, 1.59-4.81) and the absence of computer-navigation (2.26, 1.09-4.68). LCGA also identified a class of patients with poor function (23.0%). Predictors of low function trajectory class membership were, female sex (3.31, 1.95-5.63), advancing age per 10 years (2.27, 1.69-3.02), pre-surgery PCS per 10 points (0.50, 0.33-0.74), obesity (1.69, 1.05-2.72), morbid obesity (3.12, 1.55-6.27) and CCI ≥two (2.50, 1.41-4.42).

CONCLUSIONS

Modifiable predictors of poor response to TKA included baseline co-morbidity, physical and mental well-being and obesity. This provides useful information for clinicians in terms of informing patients of the expected course of longer term outcomes of TKA and for developing prediction algorithms that identify patients in whom there is a high likelihood of poor surgical response.

Minimally invasive knee arthroplasty: An overview

Minimally invasive surgery (MIS) for arthroplasty of the knee began with surgery for unicondylar knee arthroplasty (UKA). Partial knee replacements were designed in the 1970s and were amenable to a more limited exposure. In the 1990s Repicci popularized the MIS for UKA. Surgeons began to apply his concepts to total knee arthroplasty. Four MIS surgical techniques were developed: quadriceps sparing, mini-mid vastus, mini-subvastus, and mini-medial parapatellar. The quadriceps sparing technique is the most limited one and is also the most difficult. However, it is the least invasive and allows rapid recovery. The mini-midvastus is the most common technique because it affords slightly better exposure and can be extended. The mini-subvastus technique entirely avoids incising the quadriceps extensor mechanism but is time consuming and difficult in the obese and in the muscular male patient. The mini-parapatellar technique is most familiar to surgeons and represents a good starting point for surgeons who are learning the techniques. The surgeries are easier with smaller instruments but can be performed with standard ones. The techniques are accurate and do lead to a more rapid recovery, with less pain, less blood loss, and greater motion if they are appropriately performed.

Outcome Measures in Total Joint Arthroplasty: Current Status, Challenges, and Future Directions

Total joint arthroplasty (TJA) is the most commonly performed surgical procedure for the treatment of advanced degenerative joint diseases. Numerous outcome measures for TJA have been developed, which can be reported by physicians, patients, or both. Although outcome tools were traditionally centered on morbidity, mortality, and implant survival, the focus has evolved over recent years to joint-specific, disease-specific, activity-specific, general well-being, and quality of life assessments. However, despite the importance of outcome measures in a time of growing demand for TJA and increased government scrutiny fueled by high implant costs, there remains no "gold standard" method to assess the impact of TJA. The aim of this review is to evaluate the currently available literature on outcome measures in joint arthroplasty, highlighting the strengths and limitations of commonly used instruments. Because outcomes are influenced by a multitude of intangible factors, there is an increasing role for assessing patient satisfaction as a simple way to account for the complex aspects of care. Strategies including proper patient selection and establishing realistic expectations preoperatively are critical to optimizing outcomes. In an era of increasing public scrutiny, the current state of conflicting results and variable correlations among outcome measures implores the need for a standardized system that should incorporate a metric for patient satisfaction adjusted for preoperative expectations.

Patient-reported outcome measures after total knee arthroplasty: a systematic review

Objectives

A lack of connection between surgeons and patients in evaluating the outcome of total knee arthroplasty (TKA) has led to the search for the ideal patient-reported outcome measure (PROM) to evaluate these procedures. We hypothesised that the desired psychometric properties of the ideal outcome tool have not been uniformly addressed in studies describing TKA PROMS.

Methods

A systematic review was conducted investigating one or more facets of patient-reported scores for measuring primary TKA outcome. Studies were analysed by study design, subject demographics, surgical technique, and follow-up adequacy, with the ‘gold standard’ of psychometric properties being systematic development, validity, reliability, and responsiveness.

Results

A total of 38 articles reported outcomes from 47 different PROMS to 85 541 subjects at 26.3 months (standard deviation 30.8) post-operatively. Of the 38, eight developed new scores, 20 evaluated existing scores, and ten were cross-cultural adaptation of existing scores. Only six of 38 surveyed studies acknowledged all ‘gold standard’ psychometric properties. The most commonly studied PROMS were the Oxford Knee Score, New Knee Society Score, Osteoarthritis Outcome Score, and Western Ontario and McMaster Universities Osteoarthritis Index.

Conclusions

A single, validated, reliable, and responsive PROM addressing TKA patients’ priorities has not yet been identified. Moreover, a clear definition of a successful procedure remains elusive.

Cite this article: Bone Joint Res 2015;4:120–127

Validation of a prediction model that allows direct comparison of the Oxford Knee Score and American Knee Society clinical rating system

This study demonstrates a significant correlation between the American Knee Society (AKS) Clinical Rating System and the Oxford Knee Score (OKS) and provides a validated prediction tool to estimate score conversion.

A total of 1022 patients were prospectively clinically assessed five years after TKR and completed AKS assessments and an OKS questionnaire. Multivariate regression analysis demonstrated significant correlations between OKS and the AKS knee and function scores but a stronger correlation (r = 0.68, p < 0.001) when using the sum of the AKS knee and function scores. Addition of body mass index and age (other statistically significant predictors of OKS) to the algorithm did not significantly increase the predictive value.

The simple regression model was used to predict the OKS in a group of 236 patients who were clinically assessed nine to ten years after TKR using the AKS system. The predicted OKS was compared with actual OKS in the second group. Intra-class correlation demonstrated excellent reliability (r = 0.81, 95% confidence intervals 0.75 to 0.85) for the combined knee and function score when used to predict OKS.

Our findings will facilitate comparison of outcome data from studies and registries using either the OKS or the AKS scores and may also be of value for those undertaking meta-analyses and systematic reviews.

Cite this article: Bone Joint J 2015;97-B:503–9.

The KSS 2011 reflects symptoms, physical activities, and radiographic grades in a Japanese population

BACKGROUND

Cultural and ethnic differences are present both in subjective and objective measures of patient health, but scoring systems do not always reflect these differences, and so validation of outcomes tools in different cultural settings is important. Recently, a revised version of The Knee Society Score® (KSS 2011) was developed, but to our knowledge, the degree that this tool evaluates clinical symptoms, physical activities, and radiographic grades in the general Japanese population is not known.

QUESTIONS/PURPOSES

We therefore asked: (1) how KSS 2011 reflects knee conditions and function in the general Japanese population, in particular evaluating changes with increasing patient age; (2) can objective measures of physical function be correlated with KSS 2011; and (3) does radiographic osteoarthritis (OA) grade correlate with KSS 2011?

METHODS

Two hundred twenty-six people in the general Japanese population, aged 35 to 92 years, with and without knee arthritis, voluntarily participated in this cross-sectional study. Residents who had no serious disease or symptoms based on a self-assessment were recruited. This study consisted of a questionnaire including self-administered KSS 2011, physical examination, and weightbearing radiographs of the knee. Leg muscle strength, Timed Up and Go test, and body mass index (BMI) were examined in all the participants. Radiographs were graded according to the Kellgren and Lawrence scale (KL grade).

RESULTS

Multivariable linear regression analysis showed that KSS 2011 correlated with age (coefficient: -0.30±0.12, p=0.011), BMI (coefficient: -1.47±0.42, p<0.001), leg muscle strength (coefficient: 0.41±0.13, p=0.002), and Timed Up and Go Test (coefficient: -1.96±0.92, p=0.034), but not sex, as independent variables by a stepwise method. KSS 2011 was also correlated with radiographic OA evaluated by KL grade (coefficient: -12.2±2.9, p<0.001).

CONCLUSIONS

KSS 2011 reflects symptoms, physical activities, and radiographic OA grades of the knee in an age-dependent manner in the general Japanese population.

LEVEL OF EVIDENCE

Level IV, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Outcomes following large joint arthroplasty: does socio-economic status matter?

BACKGROUND

We sought to determine whether socio-economic status (SES) is an independent predictor of outcome following total knee (TKR) and hip (THR) replacement in Australians.

METHODS

In this prospective cohort study, we included patients undergoing TKR and THR in a public hospital in whom baseline and 12-month follow-up data were available. SES was determined using the Australian Bureau of Statistics 'Index of Relative Advantage and Disadvantage'. Other independent variables included patients' demographics, comorbidities and procedure-related variables. Outcome measures were the International Knee Society Score and Harris Hip Score pain and function subscales, and the Short Form Health Survey (SF-12) physical and mental component scores.

RESULTS

Among 1,016 patients undergoing TKR and 835 patients undergoing THR, in multiple regression analysis, SES score was not independently associated with pain and functional outcomes. Female sex, older age, being a non-English speaker, higher body mass index and presence of comorbidities were associated with greater post-operative pain and poorer functional outcomes following arthroplasty. Better baseline function, physical and mental health, and lower baseline level of pain were associated with better outcomes at 12 months. In univariate analysis, for TKR, the improvement in SF-12 mental health score post arthroplasty was greater in patients of lower SES (3.8 ± 12.9 versus 1.5 ± 12.2, p=0.008), with a statistically significant inverse association between SES score and post-operative SF-12 mental health score in linear regression analysis (coefficient-0.28, 95% CI: -0.52 to -0.04, p=0.02).

CONCLUSIONS

When adjustments are made for other covariates, SES is not an independent predictor of pain and functional outcome following large joint arthroplasty in Australian patients. However, relative to baseline, patients in lower socioeconomic groups are likely to have greater mental health benefits with TKR than more privileged patients. Large joint arthroplasty should be made accessible to patients of all SES.

Reliability of the "American Knee Society Score" (AKSS)

Objective

To analyze the reproducibility of the "American Knee Society Score" (AKSS) scale, and determine its measurement, in order to make it useful for the evaluation of patients with osteoarthritis or who have undergone total knee arthroplasty.

Methods

In the first interview, the AKSS was applied along with the SF-36 and WOMAC (examiner 1). After thirty minutes the same patients answered only the AKSS. After a two week break, a third additional interview with AKSS was applied (examiner 2).

Results

We selected 58 patients with a mean age of 67.4 years. In the analysis of reproducibility, by ICC, there was strong inter-examiner and intra-examiner correlation for two AKSS components. In the individual items analysis there was good correlation for "Pain", "Range of Motion", "Flexion contracture" and all items of the AKSS Function component. Validation through the Pearson coefficient showed good correlation between AKSS "Pain," WOMAC "pain" and SF-36 "Pain domain", and good correlation between the AKSS and SF-36 "Functional Capacity domain".

Conclusion

The AKSS adapted to Brazilian culture is useful and reliable for the evaluation of individuals with osteoarthritis or those who have undergone TKA.

The utility of outcome measures in total knee replacement surgery

Total knee replacement (TKR) is the mainstay of treatment for people with end-stage knee OA among suitably “fit” candidates. As a high cost, high volume procedure with a worldwide demand that continues to grow it has become increasingly popular to measure response to surgery. While the majority who undergo TKR report improvements in pain and function following surgery, a significant proportion of patients report dissatisfaction with surgery as a result of ongoing pain or poor function. Poor outcomes of TKR require care that imposes on already overburdened health systems. Accurate and meaningful capture and interpretation of outcome data are imperative for appropriate patient selection, informing those at risk, and for developing strategies to mitigate the risk of poor results and dissatisfaction. The ways in which TKR outcomes are captured and analysed, the level of follow-up, the types of outcome measures used, and the timing of their application vary considerably within the literature. With this in mind, we reviewed four of the most commonly used joint specific outcome measures in TKR. We report on the utility, strengths, and limitations of the Oxford knee score (OKS), knee injury and osteoarthritis outcome score (KOOS), Western Ontario and McMaster Universities osteoarthritis index (WOMAC), and knee society clinical rating system (KSS).

Early revisions of the Femoro-Patella Vialla joint replacement

The aim of this study was to review the early outcome of the Femoro-Patella Vialla (FPV) joint replacement. A total of 48 consecutive FPVs were implanted between December 2007 and June 2011. Case-note analysis was performed to evaluate the indications, operative histology, operative findings, post-operative complications and reasons for revision. The mean age of the patients was 63.3 years (48.2 to 81.0) and the mean follow-up was 25.0 months (6.1 to 48.9). Revision was performed in seven (14.6%) at a mean of 21.7 months, and there was one re-revision. Persistent pain was observed in three further patients who remain unrevised. The reasons for revision were pain due to progressive tibiofemoral disease in five, inflammatory arthritis in one, and patellar fracture following trauma in one. No failures were related to the implant or the technique. Trochlear dysplasia was associated with a significantly lower rate of revision (5.9% vs 35.7%, p = 0.017) and a lower incidence of revision or persistent pain (11.8% vs 42.9%, p = 0.045). Focal patellofemoral osteoarthritis secondary to trochlear dysplasia should be considered the best indication for patellofemoral replacement. Standardised radiological imaging, with MRI to exclude overt tibiofemoral disease should be part of the pre-operative assessment, especially for the non-dysplastic knee.

Patellar resurfacing versus nonresurfacing in total knee arthroplasty: a meta-analysis of randomised controlled trials

PURPOSE

Patella resurfacing or nonresurfacing in total knee arthroplasty remains controversial. The aim of this study was to evaluate the efficacy of patellar resurfacing through an evaluation of the current literature.

METHODS

We carried out a meta-analysis of randomised controlled trials comparing total knee arthroplasties performed with and without patellar resurfacing. Outcomes of reoperation, anterior knee pain and knee scores were analysed.

RESULTS

Fourteen trials assessing 1,725 knees were eligible. The absolute risk of reoperation was reduced by 4 % (95 % confidence interval, 2-6 %) in the patellar resurfacing arm (between-study heterogeneity, P = 0.05, I(2) = 42 %), implying that one would have to resurface 25 patellae (95 % confidence interval, 17-50 patellae) in order to prevent one reoperation. There was no difference between the two groups in terms of anterior knee pain, knee pain score, Knee Society score and knee function score. But in the studies followed up for a mean time of not less than five years, a difference was found between the two arms in Knee Society scores (RR = 2.14, 95 % confidence interval, 0.76-3.52; P = 0.002).

CONCLUSIONS

The available evidence indicates that patellar resurfacing reduces the risk of reoperation after total knee arthroplasty. Patellar resurfacing patients may make a difference in long-term follow-up (five or more 5 years) of Knee Society scores. In other aspects, the benefit of patellar resurfacing is limited. Additionally, more carefully and scientifically designed randomised controlled trials are required to further prove the claim.

The association between radiographic severity and pre-operative function in patients undergoing primary knee replacement for osteoarthritis

OBJECTIVE

To determine the association between radiographic osteoarthritis (OA) and pre-operative function in patients undergoing primary knee replacement.

METHODS

Single centre study examining pre-operative outcomes in a consecutive series of 525 patients who underwent primary knee replacement for OA between January 2006 and December 2007. Pre-operative data included: demographics, American Society of Anaesthesiologists (ASA) status and OA in the contralateral knee. The International Knee Society (IKS) rating and Short Form-12 (SF-12) were recorded for each patient. Pre-operative radiographs were read by a single observer for Kellgren and Lawrence (K&L) grading and Osteoarthritis Research Society International (OARSI) atlas features. Multiple linear regression was used to assess the strength of associations between radiographic OA severity and function, adjusting for clinically relevant variables.

RESULTS

Lateral tibiofemoral osteophyte grade was an independent predictor of pre-operative function as determined by the functional sub-scale of the IKS in patients undergoing primary knee replacement (coefficient=2.58, p=0.033). No associations were evident between pre-operative function and modified K&L, joint space narrowing, Ahlbäck attrition and coronal plane deformity. Other statistically significant predictors of poorer pre-operative function included: advancing age, female gender, knee pain and poorer SF-12 mental component summary scores which including osteophyte grade accounted for 24.6% of the variation in functional scores, (r=0.496).

CONCLUSION

Osteophytes in the lateral compartment of the knee were associated with pre-operative function in patients with advanced knee OA. Further studies are required which examine individual radiographic features specifically in patients with advanced knee OA to determine their relationship to pre-operative pain and function.

Associations between pre-operative radiographic changes and outcomes after total knee joint replacement for osteoarthritis

OBJECTIVE

To assess the influence of pre-operative X-ray changes on the response to total knee joint replacement (TKR).

METHODS

We included patients from one centre who underwent primary TKR (n = 478) for osteoarthritis in 2006 and 2007. The International Knee Society score (IKSS) and short form health survey were collected pre-operatively and at 1 and 2 years after surgery. Pre-operative radiographs were read to assess Kellgren and Lawrence (K-L) grading, individual radiographic features using the OARSI atlas, and subchondral bone attrition using the Ahlbach method. The main independent variable was a modified (K-L) grade. The outcome variables were the IKSS pain and function scores. Covariates included demographic features, co-morbidities, baseline pain and function, prosthesis type, and the use of patella resurfacing. Multivariable linear regression models were created to assess the relationships between pre-operative X-ray findings and pain and function outcomes.

RESULTS

On average, pain and function improved greatly following surgery. However, pain relief was unsatisfactory in about 30%, and functional improvement suboptimal in about 50%. OR (95% CI) for ongoing moderate-severe pain at 12 months for modified K-L grades; <3: 5.39 (1.23-15.69), 3a: 2.62 (1.21-5.67), 3b: 1.81 (1.00-3.26), 4a: 2.06 (1.05-4.05) when compared to 4b. OR (95% CI) for poor function at 12 months were; 3a: 2.81 (1.23-6.39) and 4a: 2.45 (1.22-4.91), when compared to 4b.

CONCLUSIONS

Patients with more severe radiographic knee damage at the time of surgery are most likely to have substantial gains in terms of both pain relief and improved function as a result of a TKR.

Posterior cruciate substituting versus posterior cruciate retaining total knee arthroplasty prostheses: a meta-analysis

PURPOSE

The arguments about whether posterior-substituting prostheses or cruciate-retaining prostheses are superior to the other after total knee arthroplasty never stop. This meta-analysis was conducted to evaluate the clinical effects of these two different designs.

METHODS

The study was performed according to the guidelines described in the Cochrane handbook for systematic reviews of interventions. Methodological features were collected and extracted by two reviewers independently.

RESULTS

Nine randomized controlled trials with 1261 knees were eligible for pooled analysis. The meta-analysis demonstrated there were no statistical differences in the Knee Society Score, Hospital for Special Surgery, Western Ontario and McMaster Universities index, tibial component alignment, femoral component alignment, tibial posterior slope, joint line, and incidence of complications with short-to medium-term follow-up (p>0.01). Statistically difference in postoperative range of motion (WMD: 4.34°, 95% CI: 3.18° to 5.50°) in favor of PS prostheses was found between groups (p<0.01).

CONCLUSION

The findings indicate there were no significant statistical differences in knee scores, radiological outcomes, and complications between the two types of implants. Statistically significant difference in postoperative ROM was found between the two groups, but no clinical difference.

Patellofemoral arthroplasty: a systematic review of the literature

Identification and management of patients with isolated patellofemoral osteoarthritis are challenging. Many of these patients present at a young age and it is important to distinguish degenerative change in the patellofemoral articulation from the other various causes of anterior knee pain. Once the diagnosis of isolated patellofemoral arthrosis has been made non-operative and conservative surgical techniques should be exhausted fully before prosthetic arthroplasty is considered. This review focuses on the use of arthroplasty for isolated patellofemoral arthrosis, in particular comparing the use of total knee against selective patellofemoral joint replacements.

Meta-analysis of navigation vs conventional total knee arthroplasty

Navigated total knee arthroplasty (TKA) is promoted as a means to improve limb and prosthesis alignment. This study involved a systematic review and meta-analysis for all randomized controlled trials in the literature from 1986 to 2009 comparing alignment outcomes between navigated and conventional TKA. Alignment outcomes were pooled using a random-effects model, and heterogeneity was explored. Twenty-three randomized controlled trials were identified comparing navigated vs conventional TKA involving 2541 patients. Patients who underwent navigated TKA had a significantly lower risk of implant malalignment at more than 3° as well as more than 2°. In addition, the risk of malalignment was reduced for the coronal plane tibial and femoral components as well as femoral and tibial slope. This meta-analysis demonstrates that navigated TKA provides significant improvement in prosthesis alignment.

Development of a new Knee Society scoring system

BACKGROUND

The Knee Society Clinical Rating System was developed in 1989 and has been widely adopted. However, with the increased demand for TKA, there is a need for a new, validated scoring system to better characterize the expectations, satisfaction, and physical activities of the younger, more diverse population of TKA patients.

QUESTIONS/PURPOSES

We developed and validated a new Knee Society Scoring System.

METHODS

We developed the new knee scoring system in two stages. Initially, a comprehensive survey of activities was developed and administered to 101 unilateral TKA patients (53 women, 48 men). A prototype knee scoring instrument was developed from the responses to the survey and administered to 497 patients (204 men, 293 women; 243 postoperatively, 254 preoperatively) at 15 medical institutions within the United States and Canada. Objective and subjective data were analyzed using standard statistical and psychometric procedures and compared to the Knee Injury and Osteoarthritis Score and SF-12 scores for validation. Based on this analysis, minor modifications led to the new Knee Society Scoring System.

RESULTS

We found the new Knee Society Scoring System to be broadly applicable and to accurately characterize patient outcomes after TKA. Statistical analysis confirmed the internal consistency, construct and convergent validity, and reliability of the separate subscale measures.

CONCLUSIONS

The new Knee Society Scoring System is a validated instrument based on surgeon- and patient-generated data, adapted to the diverse lifestyles and activities of contemporary patients with TKA. This assessment tool allows surgeons to appreciate differences in the priorities of individual patients and the interplay among function, expectation, symptoms, and satisfaction after TKA.

Joint line position correlates with function after primary total knee replacement

The role of computer-assisted surgery in maintaining the level of the joint in primary knee joint replacement (TKR) has not been well defined. We undertook a blinded randomised controlled trial comparing joint-line maintenance, functional outcomes, and quality-of-life outcomes between patients undergoing computer-assisted and conventional TKR. A total of 115 patients were randomised (computer-assisted, n = 55; conventional, n = 60).

Two years post-operatively no significant correlation was found between computer-assisted and conventional surgery in terms of maintaining the joint line. Those TKRs where the joint line was depressed post-operatively improved the least in terms of functional scores. No difference was detected in terms of quality-of-life outcomes. Change in joint line was found to be related to change in alignment. Change in alignment significantly affects change in joint line and functional scores.

Patellar resurfacing in total knee arthroplasty for osteoarthritis: a meta-analysis

PURPOSE

Whether to resurface the patella during a primary total knee arthroplasty remains a controversial issue. The aim of this study was to determine the advantages and disadvantages of patellar resurfacing during total knee arthroplasty for osteoarthritis through an evaluation of the current literature.

METHODS

A meta-analysis of randomized controlled trials comparing patellar resurfacing with nonresurfacing during total knee arthroplasties was performed. The focus of this analysis was on outcomes of reoperation, anterior knee pain and knee scores.

RESULTS

Ten trials assessing 1,003 knees were eligible. The absolute risk of reoperation was reduced by 4% (95% confidence interval, 1-7%) in the patellar resurfacing arm (between-study heterogeneity, P = 0.06, I (2) = 45%), implying that one would have to resurface 25 patellae (95% confidence interval, 14-100 patellae) in order to prevent one reoperation. Only seven trials provided adequate data of anterior knee pain for a quantitative synthesis. On the basis of those seven trials, there was no difference between the two groups in terms of anterior knee pain. Anterior knee pain after total knee arthroplasty could have multiple etiologies such as surgical factors and nonresurfaced patella is not the sole cause of this problem.

CONCLUSION

The available evidence indicates that patellar resurfacing reduce the risk of reoperation after total knee arthroplasty for osteoarthritis. Not resurfacing the patella might be considered a reasonable option, but patients must accept the increased risk of reoperation for which the quantitative evidence-based synthesis is mild. Based on the evidence provided by this study and those previously published ones, the authors do not now resurface the patella as a matter of routine for patients having a primary total knee arthroplasty for osteoarthritis.

Early functional outcome after subvastus or parapatellar approach in knee arthroplasty is comparable

PURPOSE

In total knee arthroplasty, tissue-sparing techniques are considered more important, as functional gain could become more advantageous when early mobilization is commenced. The parapatellar approach is most often used, whereas the subvastus approach is a suitable alternative. Presently, it is unknown, according to true objective measurements, which of the two is most advantageous.

METHODS

In this prospective randomized double-blind, short-term trial measurements (KSS, WOMAC, PDI, VAS, ability to perform) were obtained at day 1, day 3, 1 week, 6 weeks, and 3 months.

RESULTS

The subvastus group (n=20) showed only significantly less extension lag direct postoperative (P=0.04) compared with the parapatellar group (n=20). Other scores were not significantly different. The Dynaport®knee test, an objective performance-based tool, could not demonstrate significant differences. A blunt anatomical dissection was carried out in both observational and histological to support findings. A dense innervation of the distal vastus medialis was found. This is at risk employing the subvastus approach. Both approaches harm the suprapatellar bursa. The vastus medialis sheath must be detached distally to open the knee joint. No true separate vastus medialis obliquus could be identified.

CONCLUSION

Comparable to literature, only mild advantage employing the subvastus approach was found, but only early postoperative and not objectively. As this approach is also not suitable in every case, we will continue to use the parapatellar approach.