Improvement In Oxford Knee Score Research Articles

Fifteen-year prospective longitudinal cohort study of outcomes following single radius total knee arthroplasty.

This prospective study reports longitudinal, within-patient, patient-reported outcome measures (PROMs) over a 15-year period following cemented single radius total knee arthroplasty (TKA). Secondary aims included reporting PROMs trajectory, 15-year implant survival, and patient attrition from follow-up. From 2006 to 2007, 462 consecutive cemented cruciate-retaining Triathlon TKAs were implanted in 426 patients (mean age 69 years (21 to 89); 290 (62.7%) female). PROMs (12-item Short Form Survey (SF-12), Oxford Knee Score (OKS), and satisfaction) were assessed preoperatively and at one, five, ten, and 15 years. Kaplan-Meier survival and univariate analysis were performed. At 15 years, 28 patients were lost to follow-up (6.1%) and 221 patients (51.9%) had died, with the mean age of the remaining cohort reducing by four years. PROMs response rates among surviving patients were: one-year 63%; five-year 72%; ten-year 94%; and 15-year 59%. OKS and SF-12 scores changed significantly over 15 years (p < 0.001). The mean improvement in OKS was 18.8 (95% confidence (CI) 16.7 to 19.0) at one year. OKS peaked at five years (median 43 years) declining thereafter (p < 0.001), though at 15 years it remained 17.5 better than preoperatively. Age and sex did not alter this trajectory. A quarter of patients experienced a clinically significant decline (≥ 7) in OKS from five to ten years and from ten to 15 years. The SF-12 physical component score displayed a similar trajectory, peaking at one year (p < 0.001). Patient satisfaction was 88% at one, five, and ten years, and 94% at 15 years. In all, 15-year Kaplan-Meier survival was 97.6% (95% CI 96.0% to 99.2%) for any revision, and 98.9% (95% CI 97.9% to 99.9%) for aseptic revision. Improvements in PROMs were significant and maintained following single radius TKA, with OKS peaking at five years, and generic physical health peaking at one year. Patient satisfaction remained high at 15 years, at which point 2.4% had been revised.

Outcomes of lateral femoral sliding osteotomy in primary total knee arthroplasty for type two fixed valgus deformity.

The aim of our study was to determine the surgical outcomes of patients who underwent lateral femoral sliding osteotomy (LFSO) with total knee arthroplasty (TKA) for Ranawat's type 2 fixed valgus deformity. The consecutive patients who underwent primary TKA with posterior-stabilized implant and LFSO for fixed valgus deformity were reviewed. The radiological parameters analyzed were pre- and postoperative hip-knee-ankle (HKA) angle and tibio-femoral angle in varus-valgus stress views. The clinical outcome was measured by Oxford knee score (OKS), knee society score (KSS), and functional score (KSS-F). The complications and any reoperation were noted in the follow-up. There were total 28 patients included with an average follow-up time of 47.2 ± 24.9months. The average arc of motion was 101.3 ± 23.8° preoperatively and 102.7 ± 11.8° postoperatively (p > 0.05). The average deformity in varus and valgus stress views was 196.6 ± 4.8 and 207.8 ± 7.4°, respectively. There was significant improvement in HKA from 205.2 ± 8.3° preoperatively to 181.9 ± 3.7° postoperatively (p < 0.05). At the final follow-up, bony union of the osteotomy fragment was noted in all the patients. There was significant improvement in OKS, KSS, and KSS-F score from a preoperative 15.1 ± 3.9, 35.1 ± 10.6, and 26.6 ± 12.6 to 40.3 ± 2.9, 85.6 ± 4.8, and 89.4 ± 7.7, postoperatively (p < 0.05), respectively. One patient had acute periprosthetic joint infection that was managed with debridement and polyethylene insert exchange. Lateral femoral sliding osteotomy is an effective technique for optimal soft tissue balance in fixed valgus deformity. It provides satisfactory clinical outcome with restoration of knee alignment without using the constrained implants.

PATIENT-REPORTED OUTCOME MEASURES AFTER ELECTIVE REVISION TOTAL KNEE ARTHROPLASTY IN ELDERLY PATIENTS (&gt;85 YEARS)

AbstractIntroductionRevision total knee arthroplasty (rTKA) in elderly patients (&gt;85 years) is associated with increased mortality, hospital stay and a high rate (55%) of complications. The objective was to assess PROMs in elderly patients undergoing rTKA.MethodsA retrospective cohort study of consecutive patients undergoing rTKA at an arthroplasty centre from 2001–2022 were compared to a control group (aged 50–79y) matched for gender, diagnosis &amp; surgery year. The commonest reasons for revision in elderly patients was aseptic loosening (53/100), infection (21/100) and fracture (7/100). One-year patient-reported outcome data was available for 64%.Results100 patients underwent rTKA with a mean age of 84 years (range 80–97 years, SD 3) compared to a matched control group of younger patients (mean age 69y). Preoperative function was poor, with a mean Oxford knee score (OKS) of 40/100 in elderly and 43/100 in younger patients (p=0.164).At one-year postop, mean OKS was comparable between elderly and young patients (81 and 84/100 respectively, p=0.289). The number of patients with severe pain at one year was also comparable (4% elderly and 7% young respectively, p=0.177).The improvement in OKS for elderly patients was sustained at three (82 95% CI 58–100, 14/100 known) and five years.Overall complication rate was 54%. 14% were dead at 1 year and 56% were dead at five-years.ConclusionElderly patients undergoing elective revision TKA show a mean improvement in Oxford knee score of +38 at one year. This is the same as younger patients and is sustained at three and five years.

DOES OBESITY HAVE AN EFFECT ON PATIENT OUTCOMES AND PLATE SURVIVORSHIP IN HIGH TIBIAL OSTEOTOMY SURGERY? THE TOMOFIX ANATOMICAL MEDIAL HIGH TIBIAL PLATE

AbstractIntroductionSurgery in patients with high body mass index (BMI) is more technically challenging and associated with increased complications post-operatively. Inferior clinical and functional mid-term results for high BMI patients undergoing high tibial osteotomy (HTO) relative to normal weight patients have been reported. This study discusses the clinical, radiological and functional outcomes of HTO surgery in patients with a high BMI.MethodThis is a retrospective study on patients undergoing HTO surgery using the Tomofix anatomical MHT plate between 2017 and 2022, with follow-up period of up to 5 years. The cohort was divided: non-obese (BMI &lt;30 kg/m2) and obese (BMI&gt;30 kg/m2). Pre and post operative functional scores were collected: Oxford Knee Score (OKS), EuroQol-5D and Tegner. Complications, plate survivorship and Mikulicz point recorded.Results32 HTO procedures; 19 patients BMI &lt;30 (average 27.0) and 14 patients BMI &gt;30 (average 36.1). In BMI&lt;30 cohort, one readmission for investigation of venous thromboembolism, doppler negative; two complications: hinge fracture and stitch abscess. The five year survivorship of the plate was 100%. In BMI&gt;30 cohort, one readmission for pulmonary embolism; one complication: hinge fracture. The 5 year survivorship of the plate was 93%, 1 conversion to unicompartmental knee replacement. The average OKS improvement was 17 and 18 for BMI &lt;30 and &gt;30 respectively. Mikulicz point change was identical.ConclusionThe Tomofix anatomical MHT plate achieves good outcomes and minimal complications irrespective of BMI. Reduced plate survivorship, thus earlier conversion may be required in the obese, however higher cohort numbers are needed to confirm this.

MEDIAL UNICOMPARTMENTAL KNEE ARTHROPLASTY: BENEFITS AND RISKS OF SIMULTANEOUS BILATERAL KNEE SURGERY

AbstractIntroductionIn patients with bilateral unicompartmental knee osteoarthritis, simultaneous bilateral surgery is cost effective, with both patient-specific and wider socioeconomic benefits. There are concerns however regarding higher complication rates with bilateral knee surgery. This study compares simultaneous bilateral unicompartmental knee arthroplasty (UKA), to single side UKA in terms of complications and outcomes.MethodologyThis is a retrospective case-control study of single side medial UKA patients (controls) and simultaneous bilateral medial UKA patients (cases). All patients underwent surgery between 2018 and 2022 by a single surgeon. The two cohorts were compared for perioperative blood loss (PBL), length of stay (LOS), complications (infections, blood clots, wound problems), Oxford Knee Score improvement (OKS) and revision surgery, with a follow-up period of up to 5 years.Results64 patients were followed up comprising 55 controls and 9 cases. Average length of stay for controls was 1.55 days and 2.22 days for cases (p=0.03). Average haemoglobin drop was 7.5g/l in controls and 12.8g/l in cases (p=0.04). The OKS improvement was comparable in both groups (p=0.95) with no complications and no revision surgery in either group.ConclusionThe statistically significant differences in PBL and LOS were not clinically relevant. There were no blood transfusions and postoperative haemoglobin was within normal range in more than 60% of cases. Simultaneous bilateral unicompartmental knee arthroplasty is a financially favourable and safe option for patients with bilateral knee medial unicompartmental osteoarthritis.

Clinical Outcomes of Unicompartmental Knee Arthroplasty in Patients with Full-versus Partial-Thickness Cartilage Loss: A Systematic Review and Meta-Analysis.

The objective of the study was to compare postoperative patient-reported outcomes and reoperation rates following unicompartmental knee arthroplasty (UKA) between patients with full-thickness cartilage loss (FTCL) and partial-thickness cartilage loss (PTCL). Multiple databases, including PubMed, Embase, Cochrane Library, and CNKI, were searched until October 2019 for studies comparing the Oxford Knee Score (OKS), American Knee Society (AKS) score, and reoperation rates between patients with FTCL and PTCL following UKA. Data analysis was performed using Review Manager software. A total of 613 UKA cases from 5 retrospective cohort studies were included. The mean difference in postoperative OKSs was significantly higher by 2.92 in FTCL group than in PTCL group (95% confidence interval [CI] = -5.29 to -0.55; P = 0.02). Improvement in OKS was significantly higher by 2.69 in FTCL group than in PTCL group (95% CI = -4.79 to -0.60; P = 0.01). However, the differences in OKSs were not clinically significant. The mean difference in AKS knee scores was similar between the 2 groups (95% CI = -9.14 to -3.34; P = 0.36), whereas the pooled mean difference in AKS function scores was higher by 5.63 in FTCL group than in PTCL group (95% CI = -9.27 to -1.98; P = 0.002), which was clinically relevant. The reoperation rates were statistically higher in PTCL group than in FTCL group (odds ratio = 2.24; 95% CI = 1.15 to 4.38; P = 0.02). Patients with FTCL achieved superior postoperative patient-reported outcomes and lower reoperation rates following UKA compared with those with PTCL. Thus, we believe this procedure should only be applied to end-stage medial osteoarthritis of the knee joint.

Is success written in the stars? The effect of zodiac sign on the outcome of total knee arthroplasty.

There are 12 signs of the zodiac, each attributed with its own specific personality traits, desires and attitudes. The aim of the study was to evaluate the effect of zodiac sign on patient-reported outcome measures (PROMS) following primary total knee arthroplasty (TKA). Patients undergoing primary TKA during a 2-year period (January 2019 to December 2020) were identified retrospectively. Patient demographics, Oxford Knee Score (OKS), EuroQol 5-dimension (EQ-5D) (baseline, 1 and 2 years) and patient satisfaction scores (1 and 2 years) were collected. Each patient's zodiac sign was assigned from their date of birth. There were 509 patients (228 males [44.8%] and 281 females [55.2%]) with a mean age of 70.9 years and a mean BMI of 30.3. There were no significant differences in gender (p=0.712), age (p=0.088), BMI (p=0.660), or pre-operative OKS (p=0.539). Aries and Gemini (0.366) had the worst and Pisces the best (0.595) pre-operative EQ-5D scores (p=0.038). When adjusting for confounding, Aries (p=0.031) had a greater improvement in EQ-5D at 1 year, although this was not maintained at 2 years. When adjusting for confounding, Pisceans had significantly less of an improvement in OKS at both 1 (p=0.022) and 2 years (p=0.042) and also had a significantly lower risk of satisfaction at 2 years (odds ratio 0.41, p=0.043). Zodiac sign was associated with outcome following TKA. Pisceans had the best pre-operative EQ-5D scores, but the least improvement in the post-operative joint specific score (OKS) and were less likely to be satisfied, despite achieving an equal improvement in their health-related quality of life (EQ-5D). Aries started with the lowest pre-operative EQ-5D scores but achieved the best scores at 1 year. Our study shows that an individual's zodiac sign may serve as a useful predictive factor for functional outcomes and satisfaction following TKA. However, our findings are the result of multiple testing in a large dataset following a data trawl, and correlation does not necessarily equal causation even in a real-world registry.

Outcomes and motives for not proceeding with the second stage bilateral knee replacement: a comparison of cancelled and completed bilateral total knee arthroplasty.

Staged bilateral total knee arthroplasty (TKA) is a common treatment option for patients with bilateral symptomatic knee osteoarthritis, yet some patients do not proceed with their second procedure. Our study aimed to identify the rate and reasons why patients did not proceed with their second procedure and compare their functional outcomes, satisfaction and complication rates with those of patients who had completed a staged bilateral TKA. We determined the proportion of patients who underwent TKA but did not proceed with planned surgery for the second knee within 2 years, and compared their satisfaction with surgery, improvement in the Oxford Knee Score (OKS) and complications between groups. Our study included 268 patients: 220 patients who underwent staged bilateral TKA and 48 patients who cancelled their second procedure. The most common reason for not proceeding with the second procedure was a slow recovery after the first TKA (43.2%), followed by functional improvement in symptoms in the unoperated knee negating the need for surgery (27.3%), poor experience with the first surgery (22.7%), treatment of other comorbidities necessitating cancellation of their second procedure (4.6%) and employment reasons (2.3%). Patients who cancelled their second procedure were noted to have a worse postoperative OKS improvement (p < 0.001) and lower satisfaction rate (p < 0.001), than patients who underwent staged bilateral TKA. About one-fifth of patients scheduled for staged bilateral TKA declined to proceed with the second knee surgery within 2 years showing a substantially decreased functional outcome and satisfaction rate. However, more than one-quarter (27.3%) of patients noted improvements in their contralateral (unoperated) knee, such that a second surgery was no longer felt to be necessary.

REMOTE EVALUATION OF POSTOPERATIVE OUTCOMES USING WEARABLE SENSORS COMPARING ROBOTIC-ASSISTED AND CONVENTIONAL KNEE ARTHROPLASTY

Patient-reported outcome measures (PROMs) have failed to highlight differences in function or outcome when comparing knee replacement designs and implantation techniques. Ankle-worn inertial measurement units (IMUs) can be used to remotely measure and monitor the bi-lateral impact load of patients, augmenting traditional PROMs with objective data. The aim of this study was to compare IMU-based impact loads with PROMs in patients who had undergone conventional total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), and robotic-assisted TKA (RA-TKA).77 patients undergoing primary knee arthroplasty (29 RA-TKA, 37 TKA, and 11 UKA) for osteoarthritis were prospectively enrolled. Remote patient monitoring was performed pre-operatively, then weekly from post-operative weeks two to six using ankle-worn IMUs and PROMs. IMU-based outcomes included: cumulative impact load, bone stimulus, and impact load asymmetry. PROMs scores included: Oxford Knee Score (OKS), EuroQol Five-dimension with EuroQol visual analogue scale, and the Forgotten Joint Score.On average, patients showed improved impact load asymmetry by 67% (p=0.001), bone stimulus by 41% (p&lt;0.001), and cumulative impact load by 121% (p=0.035) between post-operative week two and six. Differences in IMU-based outcomes were observed in the initial six weeks post-operatively between surgical procedures. The mean change scores for OKS were 7.5 (RA-TKA), 11.4 (TKA), and 11.2 (UKA) over the early post-operative period (p=0.144). Improvements in OKS were consistent with IMU outcomes in the RA-TKA group, however, conventional TKA and UKA groups did not reflect the same trend in improvement as OKS, demonstrating a functional decline.Our data illustrate that PROMs do not necessarily align with patient function, with some patients reporting good PROMs, yet show a decline in cumulative impact load or load asymmetry. These data also provide evidence for a difference in the functional outcome of TKA and UKA patients that might be overlooked by using PROMs alone.

Postoperative Inpatient Rehabilitation Does Not Increase Knee Function after Primary Total Knee Arthroplasty.

Inpatient rehabilitation (IR) is a common postoperative protocol after total knee replacement (TKA). Because IR is expensive and should therefore be justified, this study determined the difference in knee function one year after TKA in patients treated with IR or outpatient rehabilitation, fast-track rehabilitation (FTR) in particular, which also entails a reduced hospital length of stay. A total of 205 patients were included in this multi-center prospective cohort study. Of the patients, 104 had primary TKA at a German university hospital and received IR, while 101 had primary TKA at a Canadian university hospital and received FTR. Patients receiving IR or FTR were matched by pre-operative demographics and knee function. Oxford Knee Score (OKS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and EuroQol visual analogue scale (EQ-VAS) determined knee function one year after surgery. Patients receiving IR had a 2.8-point lower improvement in OKS (p = 0.001), a 6.7-point lower improvement in WOMAC (p = 0.063), and a 12.3-point higher improvement in EQ-VAS (p = 0.281) than patients receiving FTR. IR does not provide long-term benefits to patient recovery after primary uncomplicated TKA under the current rehabilitation regime.

Obese Patients Achieve Good Improvements in Patient-Reported Outcome Measures After Medial Unicompartmental Knee Arthroplasty Despite a Lower Preoperative Score

BackgroundIn this study, we examined the association between obesity and patient-reported outcome measures after medial unicompartmental knee arthroplasty (MUKA), assessed through score changes, Patient Acceptable Symptom State (PASS), and minimal important change (MIC). Second, the association between obesity and early readmissions was examined. MethodsA total of 450 MUKAs (mean body mass index [BMI] 30.3, range, 19.6-53.1), performed from February 2016 to December 2020, were grouped using BMI: <30, 30-34.9, and >34.9. Oxford Knee Score (OKS), Forgotten Joint Score (FJS), and Activity and Participation Questionnaire (APQ) were assessed preoperatively and at 3, 12, and 24 months, postoperatively. The 12-month PASS and MIC were also assessed, defining PASS as OKS = 30, MIC-OKS as change in OKS = 8, and MIC-FJS as change in FJS = 14. ResultsNo significant differences in OKS change were found between BMI groups. After 12 months, patients who had a BMI of 30-34.9 had lower change in FJS (estimate −8.1, 95% CI −14.9 to −1.4) and were less likely to reach PASS (odds ratio 0.4, 95% CI 0.2-0.7) as well as MIC-FJS (odds ratio 0.5, 95% CI 0.2-0.9). Both obese groups had lower change in APQ after 12 months. Differences in 90-day readmission rates were nonsignificant between groups. ConclusionOur findings of no differences in OKS improvement between BMI groups and achieving MIC for BMI > 34.9 suggest good improvements in obese patients despite lower preoperative scores, supporting contemporary indications for MUKA. Lower APQ development and achievement of 12-month PASS may be used when addressing expectations of recovery.

Distal femoral osteotomy versus lateral unicompartmental arthroplasty for isolated lateral tibiofemoral osteoarthritis with intra-articular and extra-articular deformity: a propensity score-matched analysis

PurposeLateral unicompartmental arthroplasty (UKA) and distal femoral osteotomy (DFO) represent surgical solutions in cases of valgus malalignment and isolated lateral osteoarthritis (OA) of the knee. The aim of the present study was to assess the clinical results, complications, and the overall postoperative alignment of a series of DFO and lateral UKA with a minimum 2-year follow-up in active middle-aged patients.MethodsPatients with valgus knee and isolated lateral OA who underwent opening-wedge DFO or UKA from 2017 to 2019 were reviewed. Each patient was characterized by a joint line convergence angle (JLCA) > 3° and mechanical lateral distal femoral angle (mLDFA) < 87°. We excluded patients who underwent meniscus or osteochondral allograft during DFO. The Oxford Knee Score (OKS), Knee Injury and Osteoarthritis Outcome Score (KOOS), complications, and postoperative alignment were assessed. Propensity score matching was used to identify comparable patients.ResultsThe DFO and lateral UKA groups consisted of 29 patients each. No statistically significant differences in gender, age, body mass index (BMI), length of follow-up, or limb deformity were reported between the two groups. In the DFO group, OKS was reported to improve from 27.51 to 38.59 (p < 0.05) and KOOS from 51.14 to 67.2 (p < 0.05). Similarly, in the UKA group, OKS improved from 26.23 to 35.43 (p < 0.05) and KOOS from 50.12 to 65.91 (p < 0.05). However, the improvement in OKS and KOOS (delta) did not differ between groups (p = 0.35 and p = 0.95). The DFO and UKA groups were characterized by similar postoperative hip-knee-ankle (HKA) angle measurements of −3.26 and −3.00, respectively (p = 0.65). No patients in the UKA group underwent revision or other knee surgeries during follow-up. No infections were detected in either group. In the DFO group, no cases of nonunion or delayed union were reported. However, 40% of DFO patients underwent plate removal. One patient in each group was characterized by progression of medial OA with Kellgren-Lawrence (KL) grade > 3.ConclusionUKA and DFO represent an effective treatment in lateral knee OA with intra-articular and extra-articular deformity. Both surgeries were able to provide a significant and comparable clinical improvement.Level of evidence: III, comparative retrospective cohort study.

Translated article] Implementation of a rapid recovery protocol in total knee arthroplasty. A randomised controlled trial

BackgroundRapid recovery (RP) in total knee arthroplasty may increase the functionality while reducing costs. The aim of this study is to prove the benefits of a rapid recovery programme compared to our classic protocol. Patients and methodsWe performed a RCT (NCT03823573) in patients undergoing otal knee arthroplasty. Intervention group (RP protocol) received local infiltration of levo-bupivacaine in the periarticular tissue and supervized ambulation 4–6h after surgery. Control (C) group received a femoral nerve block with levo-bupivacaine, while a drain was used. Ambulation after its removal.All the patients completed an Oxford Knee Score prior to surgery and 6 months after discharge. An ecodoppler to assess the presence of deep vein thrombosis was made 1 month after discharge. Minimum follow-up was of 6 months. ResultsA total of 175 patients were included in the trial (92 patients in the control group, 83 patients in the RP group). There were no differences in sex, age, implanted prosthesis, haemoglobin drop, need for transfusion, range of motion on discharge (C: 82.6°, RP: 85°) and at the end of the follow-up (C: 105.1, RP: 106.6), Oxford knee score improvement (C: 17.5 points; RP: 19.3 points), patient satisfaction or re-admissions at the emergency department (C: 7.6%; RP: 10.8%).Significancy was found on time of ischaemia (C: 81.29min; RP: 85.35min; p=.03), need for morphine shots (C: 19.7%; RP: 38.6%; p=.007), hospital stay (C: 3.84 days; RP: 2.54 days, p<.0001) and time until ambulation (C: 2.46 days; RP: 0.23 days; p<.0001). ConclusionRapid recovery protocols can reduce hospital stay without increasing complications or need for re-admission.

Medium term results of the cementless Oxford mobile bearing medial unicompartmental knee replacement.

Medial Unicompartmental Knee Replacement (UKR) has well-documented benefits over Total Knee Replacement in the treatment of anteromedial osteoarthritis of the knee. There has been an increasing move from cemented to cementless UKR over the last decade. This non-design centre study assesses the initial experience using the cementless Oxford medial partial knee replacement and provides medium term revision data, as well as Patient Reported Outcome Measures (PROMs). A cohort of 200 consecutive patients undergoing medial UKR using the cementless Oxford were identified from our knee groups prospectively collected database. Cases were performed in a single centre under the care of one of four surgeons. All patients were beyond the 5-year minimum timepoint following UKR surgery in order to produce medium term results, at a mean of 7.9years. Eligible patients completed a postal questionnaire to collect PROMs: Oxford Knee Score, WOMAC and modified American Knee Society Score questionnaires in January 2020 and had their clinical records reviewed. The survivorship in our cohort was 94.5% at a mean follow up of 7.9years following surgery. There were 11 re-operations in total with a three percent risk of re-operation within the first 18months following surgery. There was a sustained improvement in Oxford Knee Score with a near 20 points improvement on pre-operative scores. Our results provide further evidence that partial knee replacements using the cementless Oxford produce good clinical outcomes. Revision rates are similar to those published in the National Joint Registry. III.

Comparing surgical strategies for end-stage anteromedial osteoarthritis : total versus unicompartmental knee arthroplasty.

AimsTreatment of end-stage anteromedial osteoarthritis (AMOA) of the knee is commonly approached using one of two surgical strategies: medial unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA). In this study we aim to investigate if there is any difference in outcome for patients undergoing UKA or TKA, when treated by high-volume surgeons, in high-volume centres, using two different clinical guidelines. The two strategies are ‘UKA whenever possible’ vs TKA for all patients with AMOA.MethodsA total of 501 consecutive AMOA patients (301 UKA) operated on between 2013 to 2016 in two high-volume centres were included. Centre One employed clinical guidelines for the treatment of AMOA allowing either UKA or TKA, but encouraged UKA wherever possible. Centre Two used clinical guidelines that treated all patients with a TKA, regardless of wear pattern. TKA patients were included if they had isolated AMOA on preoperative radiographs. Data were collected from both centres’ local databases. The primary outcome measure was change in Oxford Knee Score (OKS), and the proportion of patients achieving the patient-acceptable symptom state (PASS) at one-year follow-up. The data were 1:1 propensity score matched before regression models were used to investigate potential differences.ResultsThe matched cohort included 400 patients (mean age 67 years (SD 9.55), 213 (53%) female, mean BMI 30.2 kg/m2, 337 (84%) American Society of Anesthesiologists grade ≤ 2). We found a mean adjusted difference in change score of 3.02 points (95% confidence interval (CI) 1.41 to 4.63; p < 0.001) and a significantly larger likeliness of achieving PASS (odds ratio 3.67 (95% CI 1.73 to 8.45); p = 0.001) both in favour of the UKA strategy.ConclusionUKA and TKA are both good strategies for treating end-stage AMOA. However, when compared as a strategy, UKA achieved larger improvements in OKS, and were more likely to reach the PASS value at one-year follow-up.Cite this article: Bone Jt Open 2022;3(5):441–447.

Results of revision knee replacement for patients with isolated fixed flexion deformity after primary or revision knee replacement

BackgroundPostoperative fixed flexion deformity is a known complication of knee replacement surgery. We present our results of revision surgery for treatment of isolated fixed flexion deformity after knee replacement. Methods32 patients had revision knee replacement for fixed flexion deformity and were included in this retrospective study. Minimum follow up period was 28 months. ResultsTwo different surgical interventions had been done in these patients.Group 1 (15 patients) had revision of the femoral component, posterior capsular release and tibial component was not revised. Group 2 (18 Patients) had revision of both femoral and tibial components. One patient was included in both groups as she had both interventions.The extent of preoperative flexion deformity in group 1 was from 15 to 40 deg (mean 20.6 deg). Postoperative range of extension was 0 to 20 deg (mean 8.2 deg). In group 2, preoperative flexion deformity was 10 to 25 deg (mean 16.9 deg) and postoperative flexion deformity was 0 to 20 deg (mean 4.2 deg). The difference in improvement between the two groups was not statistically significant on Mann Whitney U test (two tailed p value 0.181) for non normal distribution. Improvement in Oxford knee score following surgery was only 1 point in both groups. ConclusionRevision for isolated fixed flexion deformity leads to improvement in range of extension, but improvement in clinical score is marginal. The choice of preservation or revision of the tibial component did not make a significant difference to the outcome.

Patient-Reported Outcomes and Risk Factors for Decreased Improvement after Patellofemoral Arthroplasty.

Patellofemoral arthroplasty (PFA) is acknowledged as the method for the treatment of isolated patellofemoral osteoarthritis (PFOA). Few previous studies have assessed the patient-reported outcomes (PROs) and risk factors of less improvement of PROs in patients undergoing PFA. A retrospective analysis was performed, including all patients who had undergone PFA. Pre- and postoperative PROs included the Oxford Knee Score (OKS) and Kujala score. Univariate and multivariate statistical analyses were performed to assess influencing factors of less improvement of PROs including the demographic factors (gender, age, body mass index, smoking, opioid usage, and duration of symptoms [DOSs]), surgical factors (concomitant surgery), and imaging factors (trochlear dysplasia [TD], patellar height, the degree of PFOA). A total of 46 PFAs were analyzed with a mean follow-up of 37 ± 7 months. The mean age at surgery was 61.1 ± 7.7 years. Patients showed significant improvement in all PROs (p < 0.001). Patients with TD preoperatively have greater improvement in OKS and Kujala score postoperatively (19.2 ± 5.0 vs. 23.1 ± 3.6, p = 0.038). Longer DOSs (≥1 year) had a greater mean improvement in OKS and Kujala score (p = 0.011 and p = 0.000). According to the measurement of patella height, patients with patella alta (Caton-Deschamps index [CDI] ≥1.3) showed less improvement in both OKS and Kujala score (p = 0.000 and p = 0.002). PFA is a safe and efficient surgery with good PROs. Patella alta with a CDI ≥1.3 and duration of preoperative symptoms ≤ 1 year were risk factors for decreased OKS and Kujala score improvement, while the preoperative presence of TD was significantly predictive factors for increased OKS improvement.

The oxford knee score minimal clinically important difference for revision total knee arthroplasty

BackgroundMinimal clinically important difference (MCID) is crucial for interpreting meaningful improvements in patient-reported outcome measures (PROMs). No previous study has evaluated the MCID for the Oxford Knee Score (OKS) in revision total knee arthroplasty (TKA). This study aimed to propose the OKS MCID for revision TKA. MethodsProspectively collected data from 191 patients who underwent revision TKA at a single institution was analysed. Clinical assessment was performed preoperatively and at 2 years using OKS and Short-Form 36 Physical Component Score (SF-36 PCS). MCID was evaluated with a three-pronged methodology, using (1) anchor-based method with linear regression, (2) anchor-based method with receiver operating characteristic (ROC) and area under curve (AUC), (3) distribution-based method with standard deviation (SD). The anchors used were improvement in SF-36 PCS ≥ 12, patient satisfaction, and implant survivorship following revision TKA. ResultsThe MCID determined by anchor-based linear regression method using improvements in SF-36 PCS was 4.9 points. The MCID determined by anchor-based ROC was 10.5 points for satisfaction (AUC = 74.8%) and 13.5 points for implant survivorship (AUC = 73.7%). The MCID determined by distribution-based method of 0.5 SD was 4.7. ConclusionThe proposed MCID for OKS following revision TKA is 4.9 points. Patients who achieve an improvement in OKS of at least 10.5–13.5 points by 2 years are likely to be satisfied with their surgery and not require a subsequent re-revision TKA. Patients undergoing revision TKA should aim for an improvement in OKS of at least 10.5–13.5 points as a target score.

Comparison of functional outcome of simultaneous and staged bilateral total knee arthroplasty : systematic review of literature

Safety of simultaneous bilateral TKA (simBTKA) and staged BTKA (staBTKA) have been compared in previous systematic reviews but functional outcome remains neglected aspect of the debate. We performed a systematic review of contemporary literature to compare the functional outcome of simBTKA and staBTKA. We searched PubMed/MEDLINE, EMBASE and Cochrane Central Database to identify all articles published between 2000 and July 2020 that evaluated the outcome of patients undergoing BTKA either in simultaneous or staged manner. Ten articles were identified which met the inclusion criteria. Functional outcome was reported in terms of Knee Society score (KSS), range of motion (ROM), Oxford Knee Score (OKS) and Western Ontario and McMaster University score (WOMAC) in seven, five, four and two studies respectively. KSS gained on average 66.6 points (47.5-95.3) for simBTKA and 65.1 points (44.4-97.2) for staBTKA without significant difference between two groups. There was no difference in post-operative ROM (maximum post-operative flexion being 124.4 and 125.1 for simBTKA and staBTKA groups respectively). Mean improvement in OKS ranged from 20 to 32.6 for simBTKA and 21.6 to 33.1 for staBTKA. There was moderate evidence to suggest that both simultaneous BTKA and staged BTKA produce equivalent improvement in functional scores.

Unicompartmental Knee Replacement in Obese Patients: A Systematic Review and Meta-Analysis.

Thanks to modern surgical techniques and implants, traditional exclusion criteria for unicompartmental knee arthroplasty (UKA) are no longer considered contraindications. The aim of this study is to clarify the impact of obesity on functional outcomes and revision rates of UKA. We performed a comprehensive systematic review using PubMed–Medline, Google Scholar and Cochrane Central. Then, we extracted data related to body mass index (BMI), age and follow-up, functional outcome scores and rate of revisions (all-cause, aseptic and septic). Patients were stratified according to BMI into two groups: non-obese (BMI < 30) and obese (BMI ≥ 30). We identified 22 eligible studies, of which 13 were included in the meta-analysis. Patients with a BMI > 30 had a significantly higher likelihood for revision (p = 0.02), while the risk of septic revision was similar (p = 0.79). The clinical outcome measures showed a significant difference in favor of patients with a BMI < 30 (p < 0.0001). The improvements in Oxford Knee Score and Knee Society Score were significant in both obese and non-obese patients, although the latter showed inferior results. The results of this systematic review and meta-analysis show that BMI is not a contraindication to UKA. However, obese patients have a higher risk for aseptic failure and lower improvement in clinical scores compared to non-obese patients.