Postponement of total knee arthroplasties due to pandemic causes significant deterioration on patients' preoperative knee and quality of life scores

Introduction

Elective surgeries were postponed during the COVID-19 pandemic to alleviate healthcare strains, affecting majority of elective orthopaedic surgeries such as total knee arthroplasties (TKAs). The aim of this study is to evaluate the impact on knee function and quality of life of patients who had their planned TKA postponed due to the pandemic.

Methods

This is a retrospective analysis of data collected in a tertiary hospital. Patients included were diagnosed with primary knee osteoarthritis and they were initially scheduled for primary TKA between January to April 2020 but surgery was postponed by at least 6 months from the initial operative date. 160 patients were included in this study (53 males and 107 females, mean age 68.0 ± 8.1). Patients were assessed prior to initial surgery date and assessed again, prior to the postponed surgery date. Clinical scores included Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee scores (OKS) and Short-Form 36 Physical and Mental Component Scores. (SF36 PCS and MCS). Paired T-test was performed for parametric data whereas Wilcoxon signed-rank analysis was performed for non-parametric data.

Results

Comparing initial preoperative versus postponement preoperative scores, the cohort had significantly poorer KSKS (38.4 ± 15.4 and 36.5 ± 15.4, p = 0.034), SF36 PCS (34.3 ± 9.2 and 32.7 ± 8.6, p = 0.02) and OKS (34.9 ± 0.77 and 35.8 ± 8.6, p = 0.02) scores respectively.

Conclusion

The postponement of elective TKAs has resulted in a significant deterioration of knee scores and physical quality of live scores of patients in a short span of 6 months. Further studies can evaluate if there are repercussions on long term TKAs outcomes.

Level of evidence

Retrospective study, Level III.

Unicompartmental knee arthroplasty in obese patients, poorer survivorship at 15 years

Introduction

The preclusion of obese patients from unicompartmental knee arthroplasty (UKA) has increasingly been challenged. This study aimed to evaluate the impact of Body Mass Index (BMI) on UKA at 15-year follow-up.

Materials and methods

169 unilateral UKA patients from 2003 to 2007 were followed-up prospectively for at least 15 years. 70 patients were left for analysis after accounting for patient demise, revision surgery and loss to follow-up. 48 of these patients (69%) were in the Control group (BMI <30 kg/m2) and 22 (31%) were in the Obese group (BMI ≥30 kg/m2). Patients were assessed before and after operation using the Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee Score (OKS), and Physical (PCS) and Mental (MCS) component of the Short Form 12. Survivorship analysis was also performed.

Results

Obese patients went through UKA at an earlier age than the non-obese patients (54.7 ± 4.7 years compared to 59.9 ± 7.8 years, p = 0.005). At 2, 10, and 15-year follow-up, both groups achieved clinically significant improvements in outcomes. There was no significant association found between obesity and outcome using multiple linear regression. While propensity matching found PCS improvement at 2 years to be greater in obese patients, no significant association between obesity and 15-year outcome was found. All 13 patients who required revision, underwent total knee arthroplasty (TKA). The overall 15-year survivorship was 74.2% within the obese group and 92.4% within the control group.

Conclusion

Compared to non-obese patients, obese patients had poorer 15-year survivorship with greater odds of requiring revision surgery. However, assuming implant survival, obese patients can expect a non-inferior outcome relative to their non-obese counterparts in all patient reported outcome measures 15 years after surgery.

Severe genu varus deformity does not affect enhanced recovery after surgery total knee arthroplasty outcomes

INTRODUCTION

Enhanced recovery after surgery (ERAS) has been increasingly adopted in orthopaedic surgery. Although not an exclusion criterion, patients undergoing total knee arthroplasty (TKA) with preoperative severe varus deformity may be less likely to be enrolled for ERAS. This study aimed to compare the success of ERAS TKA between patients with severe preoperative varus deformities (≥ 15° varus) and the control group (< 15° varus to 14° valgus). Our secondary aim was to compare postoperative complications and functional outcomes between the two groups.

MATERIALS & METHODS

310 TKAs performed from August 2019 to February 2021 were analyzed with a follow-up of 6 months postoperatively. The primary outcome, ERAS TKA success, was defined as length of hospital stay of < 24 h. Other parameters included 30-day postoperative complications and clinical outcomes such as the original Oxford Knee Score (OKS), the Knee Society Knee (KSKS) and Function Score (KSFS), Visual Analog Scale for Pain (VAS-P), 36-Item Short-Form Health Survey (SF-36) Physical Component Summary (PCS) and SF-36 Mental Component Summary (MCS).

RESULTS

There were 119 patients in the severe deformity group and 191 patients in the control group. There were no significant differences in ERAS success between the severe deformity group and control group, with both groups achieving similarly high rates (> 90%) of ERAS success. There were also no differences in 30-day postoperative complications and 6-month postoperative clinical outcomes.

CONCLUSION

Patients with severe preoperative varus deformity undergoing ERAS TKA achieved high ERAS success rates (> 90%). Genu varum is not a contraindication for ERAS TKA.

Functional outcome of direct anterior versus posterior approach in total hip arthroplasty: a propensity-matched Asian study

INTRODUCTION

The direct anterior approach (DAA) to total hip arthroplasty (THA) is a surgical approach that minimises soft tissue trauma, resulting in faster rehabilitation when compared to a posterior approach (PA). This study aimed to evaluate the difference between the two groups in an Asian cohort using propensity score matching.

METHODS

A retrospective review of prospectively collected registry data of 794 primary THAs was performed. The effects on patients with DAA THA versus patients with PA THA were investigated. Propensity scores were generated using logistic regression to adjust for confounding variables of age, gender, body mass index and diagnosis. Data analysis was performed, and statistical significance was defined as a P value < 0.05.

RESULTS

The average length of stay (LOS) for the PA group and DAA group was 5.4 days and 2.9 days, respectively (P < 0.001). One (1.9%) patient from the PA group suffered a posterior dislocation 6 months after surgery and subsequently underwent revision surgery 2 years later. No dislocations were detected in the DAA group. The DAA group had better functional outcome, satisfaction and expectation scores at 6 months and 2 years.

CONCLUSION

In this study, patients who underwent DAA THA had better functional outcome at 2 years and almost 2 days shorter overall LOS than those who underwent PA THA. Therefore, the DAA to THA is a novel technique that has shown improved functional outcomes, with fewer complications compared to PA THA.

Novel morphogenic knee implant delivers comparable mid-term outcomes as compared to conventional non-morphogenic implants

INTRODUCTION

Conventional total knee arthroplasty (C-TKA) implants have well-established mid- and long-term outcomes. The novel TKA (N-TKA) implants provide morphogenic implant components with smaller size increments to facilitate anatomical replication. The aim of the study is to evaluate if these advantages provides better clinical outcomes.

MATERIALS AND METHODS

Registry data prospectively collected within a single institution from 2014 to 2018 was reviewed and propensity score matching was performed to match C-TKA to N-TKA. 70 pairs of cruciate retaining (CR) TKA and 116 pairs of posterior stabilized (PS) TKA were identified. Range of motion, SF-36, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS) and Oxford Knee Score (OKS) were assessed preoperatively, 6 and 24 months postoperatively. Satisfaction was assessed 6 and 24 months postoperatively. Independent T test was performed for parametric data, whereas Wilcoxon rank-sum analysis was performed for non-parametric data.

RESULTS

Both C-TKA and N-TKA cohorts demonstrated statistically significant improvement for KSKS, KSFS, OKS and SF-36 at 6 and 24 months postoperatively. C-TKA CR patients had better flexion at 6 months as compared to N-TKA CR (108.7° versus 98.3°, respectively, p = 0.046). At 24 months, there was no difference between C-TKA and N-TKA for range of motion, KSKS, KSFS, OKS and SF-36 PCS, regardless of insert type (p > 0.05).

CONCLUSIONS

Both models showed great postoperative improvements in KSFS, KSKS, OKS and SF-36 and have comparable early and mid-term outcomes, suggesting that N-TKAs are suitable substitutes for C-TKA. Longer follow-up studies are required to evaluate the long-term outcomes of N-TKAs.

LEVEL OF EVIDENCE

lll.

Cost-Effectiveness of Robot-Assisted Total Knee Arthroplasty: A Markov Decision Analysis

BACKGROUND

Robot-assisted total knee arthroplasty (rTKA) may improve clinical outcomes for patients who have end-stage osteoarthritis of the knee. However, the costs of rTKA are high, and there is a paucity of data evaluating the cost-effectiveness of rTKA. We aimed to analyze the cost per quality-adjusted life-year (QALY) of rTKA relative to manual TKA.

METHODS

A Markov decision analysis was performed using known parameters for costs, outcomes, implant survivorships, and mortalities. The cost-effectiveness of rTKA relative to manual TKA was assessed for end-stage knee osteoarthritis patients who had a mean age of 65 years (range, 27 to 94 years). The rTKA costs were calculated for a pay-per-use contract robot.

RESULTS

Using the Markov Model with an annual case volume of 500 patients and a mean age of 65 years, the overall health gain per patient was 13.34 QALYs after rTKA and 13.31 QALYs after manual TKA. This resulted in an overall gain in QALYs of 0.03 for each patient undergoing an rTKA compared with manual TKA and an incremental cost of $128,526 Singapore Dollars per QALY.

CONCLUSION

Robotic TKA is not a cost-effective alternative to conventional TKA using a pay-per-use contract robot.

Telescoping Allograft Prosthetic Composite (APC) Reconstruction of the Femur Following Revision Arthroplasty for Neglected Developmental Dysplasia of the Hip (DDH)

Although uncommon, neglected developmental dysplasia of the hip (DDH) poses a technically demanding problem for treating surgeons. Due to the congenital malformation of the native hip joint and distortion of the surrounding soft tissue, addressing limb-length discrepancy is intricate. Despite detailed planning and meticulous soft tissue handling, complications can be difficult to avoid in these patients even under experienced hands. In this case report, we present a 73-year-old lady with neglected DDH who had undergone initial total hip arthroplasty and subsequent revision surgery that failed due to aseptic loosening. Due to limited length in the distal femur, we used a telescoping allograft prosthetic composite (APC) to provide adequate length to the native distal femur during revision with proximal femur fixation. This technique can help avoid the need for total femur replacement (TFR) surgery, which is more invasive and may require tibia replacement.

Long-Term Outcomes of Articular Surface Replacement (ASR) Implant in Hip Arthroplasty: A Single Institution Review

Various metal-on-metal (MoM) total hip replacements (THRs) have been found to have high short-term failure rates due to adverse responses to metal debris (ARMD). As a consequence, several low-performing THRs have been removed off the market. The purpose of this research was to look at the at least five-year outcomes of patients who had MoM hip arthroplasty at our institution. In one specialised centre between 2007 and 2008, 24 Articular Surface Replacement (ASR^TM, DePuy, Warsaw, IN, USA) MoM THRs (in 24 patients, mean age: 56.4 years) were implanted. DePuy ASR hip prosthesis for osteoarthritis or hip fractures were employed in the THR system. All patients were summoned back for a clinical assessment, and imaging was done as needed. The average period of follow-up was 8.0 years (6.0-10 years). In all, eight instances (33.3%) were discovered to have pseudotumors, four hips (16.7%) were revised, and one (4.1%) was operated for ARMD. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Oxford ratings improved statistically significantly five years after surgery in all three areas of pain, disability, and stiffness; however, there was no statistically significant change in the 36-Item Short Form Survey (SF-36) (mental) score. MoM hip arthroplasty had a greater revision incidence at five years in our group, presumably owing to the adoption of a smaller femoral head size.

Preoperative mental distress is associated with poorer physical improvements after revision total hip arthroplasty

Aims

Despite the increasing prevalence of mental health disorders in revision arthroplasty patients, the impact of preoperative mental distress on functional outcomes after revision total hip arthroplasty (rTHA) remains unclear. Our study aims to investigate the impact of preoperative mental distress on functional outcomes after rTHA.

Methods

Prospectively collected data of 84 rTHAs was extracted from a single institution's joint replacement registry. Preoperative Short Form-36 (SF-36) mental component summary (MCS) was used to dichotomize patients to those who were distressed (MCS <50) and non-distressed (MCS ≥50). Multivariable analysis was used to analyze the impact of preoperative mental distress on various outcomes such as the SF-36 physical component summary (PCS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Hip Score (OHS), patient satisfaction and expectation fulfilment at 6 months and 2 years postoperatively.

Results

Compared to non-distressed patients, patients with preoperative mental distress had poorer improvements in PCS (+11.4 vs + 16.9, p = 0.007) and lower rates of minimal clinically important difference (MCID) attainment (55.2% vs 73.0%, p = 0.026) at 2 years postoperatively. However, there were no significant differences in improvements for WOMAC and OHS (p > 0.05). Despite experiencing greater absolute improvements in MCS (+12.1 vs -2.1, p < 0.001) and higher MCID attainment rates (65.5% vs 24.3%, p = 0.005) at 2 years, preoperatively distressed patients had lower MCS levels compared to their non-distressed counterparts at all time points (p-value<0.05). There were no significant differences in patient satisfaction (p = 0.509) or expectation fulfilment (p-value = 0.342) at 2 years postoperatively.

Conclusion

Revision THA led to substantial mental health improvements in patients with preoperative mental distress. Despite this, preoperative mental distress was associated with poorer physical improvements after surgery.

Revision total hip arthroplasty is associated with poorer clinically meaningful improvements and patient satisfaction compared to primary total hip arthroplasty

Purpose

This study aims to compare PROM improvements and satisfaction rates between revision (rTHA) and primary total hip arthroplasty (pTHA).

Methods

84 rTHAs were propensity-score matched to 168 pTHAs using patient demographics and preoperative PROMs. Multiple regression was used to evaluate differences in PROMs, minimal clinically important difference (MCID) attainment and patient satisfaction.

Results

Compared to pTHA patients, rTHA patients had poorer MCID attainment for OHS, WOMAC and SF-36 PCS and lower satisfaction rates at 2-years postoperatively (p < 0.05).

Conclusion

Patients undergoing rTHA are likely to have poorer outcomes and should be appropriately counselled to better manage their preoperative expectations.

Level of evidence

Level II.

Similar postoperative outcomes after total knee arthroplasty with measured resection and gap balancing techniques using a contemporary knee system: a randomized controlled trial

PURPOSE

The Attune® Knee System provides new instrumentation to achieve symmetric flexion/extension gaps in total knee arthroplasty (TKA). However, there is limited information on the optimal TKA technique using this system. The aim of this randomised controlled trial was to determine which surgical technique results in better postoperative clinical outcomes after TKA using the contemporary Attune^® Knee System: the measured resection or gap balancing technique.

METHODS

A prospective randomized controlled trial was conducted with 100 patients undergoing TKA using measured resection (n = 50) or gap balancing (n = 50) technique. The measured femoral sizer was used in the measured resection group, while the balanced femoral sizer was used in the gap balancing group. Functional outcomes and quality of life were assessed preoperatively and at 6 months and 2 years post-surgery, using the Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee Score (OKS), the Physical Component Score (PCS) and Mental Component Score (MCS) of Short-Form 36 (SF-36). Using weight-bearing coronal radiographs, the hip-knee-ankle angle (HKA), coronal femoral component angle (CFA), coronal tibial component angle (CTA) and joint line height were also evaluated for each patient.

RESULTS

There were no significant differences in the functional scores or the proportion of patients from each group who were satisfied or had their expectations fulfilled at 6 months or 2 years post-surgery. There was also no significant difference in the number of patients who attained minimum clinically important difference (MCID) postoperatively between the groups. Postoperatively, there was no significant difference in the number of HKA outliers between the groups (p = 0.202). The postoperative CFA (p = 0.265) and CTA (p = 0.479) were similar between the groups. There was also no significant difference in the absolute change (p = 0.447) or proportion of outliers (p = 0.611) for joint line height between the groups.

CONCLUSION

Both measured resection and gap balancing techniques resulted in comparable functional and quality of life outcomes up to 2 years post-surgery. Both techniques appear to be equally effective in achieving excellent outcomes with the Attune^® Knee System.

LEVEL OF EVIDENCE

I.

Improving Acetabular Component Positioning in Supine Direct Anterior Total Hip Arthroplasty with a Transparency Template: A Novel, Simple, and Cost-effective Technique

Purpose

A novel and simple method to ensure accurate acetabular component anteversion and inclination intraoperatively with the use of a transparency template is described.

Materials and Methods

Patients who underwent total hip arthroplasty (THA) via direct anterior approach (DAA) from June 2019 to January 2020 were included. A transparency template that can be placed over the image intensifier monitor to allow surgeons an accurate reading of the acetabular component position intraoperatively was designed, developed and utilized to determine effectiveness. The first template consists of two perpendicular lines indicating the “trans-ischial line” and the “pubic symphysis/coccyx”. The second template consist of a line indicating 45° inclination and parallel lines of corresponding distances apart required to achieve 20° anteversion based on Lewinnek's formula: version=sin^-1 (D1/D2), where D1: minor axis and D2: major axis of the component. This template was used throughout the acetabular part of the surgery, from reaming to impaction of component. Postoperative acetabular inclination, anteversion, surgical duration, length of stay, as well as complications were recorded.

Results

Twenty-six patients were included in this study. Mean postoperative acetabular cup inclination was 43.46±3.09° and mean version was 19.98±2.89°. A total of 21 patients (80.8%) fell within the Callanan safe zone and all 26 patients (100%) were within the Lewinnek safe zone.

Conclusion

The transparency template is a simple, reproducible, and effective tool with a minimal learning curve and no requirement for expensive equipment. This template has the potential to assist surgeons, especially those who are less experienced with DAA THA, in obtaining better postoperative radiographic outcomes.

Development and internal validation of machine learning algorithms to predict patient satisfaction after total hip arthroplasty

BACKGROUND

Patient satisfaction is a unique and important measure of success after total hip arthroplasty (THA). Our study aimed to evaluate the use of machine learning (ML) algorithms to predict patient satisfaction after THA.

METHODS

Prospectively collected data of 1508 primary THAs performed between 2006 and 2018 were extracted from our joint replacement registry and split into training (80%) and test (20%) sets. Supervised ML algorithms (Random Forest, Extreme Gradient Boosting, Support Vector Machines, Logistic LASSO) were developed with the training set, using patient demographics, comorbidities and preoperative patient reported outcome measures (PROMs) (Short Form-36 [SF-36], physical component summary [PCS] and mental component summary [MCS], Western Ontario and McMaster's Universities Osteoarthritis Index [WOMAC] and Oxford Hip Score [OHS]) to predict patient satisfaction at 2 years postoperatively. Predictive performance was evaluated using the independent test set.

RESULTS

Preoperative models demonstrated fair discriminative ability in predicting patient satisfaction, with the LASSO model achieving a maximum AUC of 0.76. Permutation importance revealed that the most important predictors of dissatisfaction were (1) patient's age, (2) preoperative WOMAC, (3) number of comorbidities, (4) preoperative MCS, (5) previous lumbar spine surgery, and (6) low BMI (< 18.5).

CONCLUSION

Machine learning algorithms demonstrated fair discriminative ability in predicting patient satisfaction after THA. We have identified modifiable and non-modifiable predictors of postoperative satisfaction which could enhance preoperative counselling and improve health optimization prior to THA.

Subchondroplasty for Bone Marrow Lesions in the Arthritic Knee Results in Pain Relief and Improvement in Function

Subchondroplasty is a relatively new joint preserving procedure, which involves the localized injection of calcium pyrophosphate bone substitute into the bone marrow lesion. The advent of magnetic resonance imaging (MRI) has greatly facilitated the identification of these bone marrow lesions. We investigated the clinical efficacy of subchondroplasty in the treatment of symptomatic bone marrow lesions in the knee, including knees with preexisting osteoarthritis. This study comprised of 12 patients whose knees were evaluated with standard radiographs and MRI to identify and localize the bone marrow lesions. They then underwent subchondroplasty under intraoperative radiographic guidance. Preoperative and postoperative visual analog scale (VAS) pain scores, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, and Knee Injury and Arthritis Outcome Scores (KOOS) were obtained. VAS scores improved significantly from 7.5 ± 1.8 before surgery to 5.2 ± 2.7 after surgery. This further improved to 2.1 ± 2.4 at the one-year follow-up. KOOS scores improved significantly from 38.5 ± 17.0 before surgery to 73.2 ± 19.0 at the one-year follow-up. WOMAC scores improved significantly from 47.8 ± 20.5 before surgery to 14.3 ± 13.2 at the one-year follow-up. Subchondroplasty offers an effective way to treat subchondral bone marrow lesions in the arthritic knee, resulting in improvement in symptoms and early return to activity. Long-term studies are required to evaluate if these benefits can last. This is a Level II study.

Is constraint implant with metaphyseal sleeve a viable option for revision TKR with preoperative coronal plane instability and bone defect?

BACKGROUND

Metaphyseal sleeves have been used as metaphyseal filling implants to address bone loss during revision total knee replacements (TKRs). This study aims to compare the 2-year clinical and radiological outcomes of constraint implant with bone defect and constraint implant without or minimal bone defect in revisions TKR with preoperative coronal plane instability.

MATERIALS AND METHODS

Seventeen cases of constraint implants with metaphyseal sleeve matched paired with 34 cases of constrained condylar knee (CCK) prosthesis. Age, gender, body mass index and aetiology for revision surgery were recorded. Clinical outcome measures included Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS), Oxford Knee Score (OKS), physical component summary (PCS) and mental component summary (MCS). Radiological outcome measures included joint line changes, hip-knee-ankle angle (HKA), coronal femoral angle (CFA) and coronal tibial angle (CTA).

RESULT

Patients in sleeve group showed significant improvement in KSKS, KSFS and OKS (38 ± 7, 35 ± 6 and 20 ± 2 points, respectively, p < 0.001), while they were 19 ± 3 and 6 ± 2 points for PCS and MCS, respectively (p < 0.001 and p = 0.021). These postoperative scores after surgery were similar between the two groups at 6 months and 2 years. The sleeve provides comparable result in joint line restoration; the postoperative HKA, CFA and CTA were all comparable between the two groups.

CONCLUSION

Metaphyseal sleeve with constraint implant is a viable option for revision TKR with preoperative coronal plane instability and significant bone defect. It is able to achieve similar clinical outcomes and joint line restoration compared to CCK prosthesis at 2-year follow-up.

Patient-reported Outcome Measures of Revision Total Hip Arthroplasty for Prosthetic Joint Infection is not Inferior to Aseptic Revision Total Hip Arthroplasty

Introduction:

This study aims to investigate whether patients undergoing two-stage revision total hip arthroplasty (THA) for prosthetic joint infection (PJI) and one-stage revision THA for aseptic reasons have similar clinical outcomes and patient satisfaction during their post-operative follow-up. We hypothesise that the two-stage revision THA for PJI is associated with poorer outcomes as compared to aseptic revision THA.

Materials and Methods:

We reviewed prospectively collected data in our tertiary hospital arthroplasty registry and identified patients who underwent revision THA between 2001 and 2014, with a minimum of two years follow-up. The study group (two-stage revision THA for PJI) consists of 23 patients and the control group (one-stage revision THA for aseptic reasons) consists of 231 patients. Patient demographics, Western Ontario and McMaster Universities Arthritis Index (WOMAC), Oxford Hip Score (OHS), Short Form-36 (SF-36) scores and patient reported satisfaction were evaluated. Student’s t-test was used to compare continuous variables between the two groups. Statistical significance was defined as p <0.05.

Results:

The pre-operative demographics and clinical scores were relatively similar between the two groups of patients. At two years, patients who underwent revision THA for PJI reported a better WOMAC Pain Score and OHS as compared to aseptic revision THA. A similar proportion of patients were satisfied with their results of surgery in both groups (p=0.093).

Conclusions:

Although patients who underwent revision THA for PJI had poorer pre-operative functional scores (WOMAC function and SF-36 PF), at two years follow-up, these two groups of patients have comparable post-operative outcomes. Interestingly, patients who had revision THA for PJI reported a better clinical outcome in terms of OHS and WOMAC Pain score as compared to the aseptic group. We conclude that the revision THA for PJI is not inferior to aseptic revision THA in terms of patient satisfaction and clinical outcomes.

Induced Membrane Bone Grafting Technique for Treatment of Large Postinfectious Acetabular Bone Defects

Management of large acetabular bone defects is challenging. The Masquelet technique has successfully reconstructed segmental defects in long bones arising from trauma, tumors, or infection but not been described for large acetabular defects. We present 3 cases of large acetabular bone defects arising from chronic prosthetic joint infection, treated via a novel induced membrane bone grafting technique, drawn from the Masquelet technique. All cases showed satisfactory clinical and radiological outcomes at midterm follow-up. This technique holds promise and can be an alternative means when treating large acetabular bone defects.

Robotic-Arm Assisted Direct Anterior Total Hip Arthroplasty; Improving Implant Accuracy

INTRODUCTION

The aim of this study was to investigate the accuracy of implant position of robotic-arm assisted total hip arthroplasty (THA) via the direct anterior approach (DAA).

MATERIALS AND METHODS

All patients who underwent robotic-arm assisted DAA THA (MAKO Surgical Corp., Ft. Lauderdale, Florida) from November 2018 to January 2020 were prospectively followed up. Pelvis indices (limb length discrepancy, femoral and hip offset, implant inclination, and anteversion), surgical duration, length of stay, and complications were recorded. To further evaluate the accuracy of robotic-arm assisted THA, patients who underwent manual DAA THA by the same surgeon were match-paired with the study group.

RESULTS

Twenty-five patients underwent robotic-arm assisted DAA THR. Limb length discrepancy was restored to 0.1mm (±3.4mm) from 10.0mm (±6.4mm) postoperatively. Preoperatively, the difference in femoral offset was 5.1mm (±5.1mm), and this was corrected to 1.9mm (±6.5mm) postoperatively. Nine cases had target inclination of 40° and mean inclination achieved was 40.7° (±0.9°). Sixteen cases had target inclination of 45° and mean inclination achieved was 45.3° (±1.0°). Mean anteversion was 19.5° (±2.4°). Propensity matched analysis showed that the root mean square errors for manual cup implantation compared to the robotic-arm assisted group was 2.3 times higher for anteversion and 6.3 times higher for inclination. Fourteen (56%) of the cups were within Callanan safe-zone and 18 (72%) within Lewinnek safe-zone in the manual group compared to 18 (72%) and 25 (100%), respectively, in the robotic-arm assisted group.

CONCLUSION

Combining the muscle-sparing technique of DAA with the improved implant placement with the robotic-arm assisted platform is a promising solution to improving THA outcomes.

Robotic-Arm Assisted Direct Anterior Total Hip Arthroplasty; Improving Implant Accuracy

INTRODUCTION

The aim of this study was to investigate the accuracy of implant position of robotic-arm assisted total hip arthroplasty (THA) via the direct anterior approach (DAA).

MATERIALS AND METHODS

All patients who underwent robotic-arm assisted DAA THA (MAKO Surgical Corp., Ft. Lauderdale, Florida) from November 2018 to January 2020 were prospectively followed up. Pelvis indices (limb length discrepancy, femoral and hip offset, implant inclination, and anteversion), surgical duration, length of stay, and complications were recorded. To further evaluate the accuracy of robotic-arm assisted THA, patients who underwent manual DAA THA by the same surgeon were match-paired with the study group.

RESULTS

Twenty-five patients underwent robotic-arm assisted DAA THR. Limb length discrepancy was restored to 0.1mm (±3.4mm) from 10.0mm (±6.4mm) postoperatively. Preoperatively, the difference in femoral offset was 5.1mm (±5.1mm), and this was corrected to 1.9mm (±6.5mm) postoperatively. Nine cases had target inclination of 40° and mean inclination achieved was 40.7° (±0.9°). Sixteen cases had target inclination of 45° and mean inclination achieved was 45.3° (±1.0°). Mean anteversion was 19.5° (±2.4°). Propensity matched analysis showed that the root mean square errors for manual cup implantation compared to the robotic-arm assisted group was 2.3 times higher for anteversion and 6.3 times higher for inclination. Fourteen (56%) of the cups were within Callanan safe-zone and 18 (72%) within Lewinnek safe-zone in the manual group compared to 18 (72%) and 25 (100%), respectively, in the robotic-arm assisted group.

CONCLUSION

Combining the muscle-sparing technique of DAA with the improved implant placement with the robotic-arm assisted platform is a promising solution to improving THA outcomes.

Functional outcome and quality of life in patients with hip fracture after total knee arthroplasty

INTRODUCTION

Hip fractures are a cause of significant morbidity. While rare, ipsilateral hip fractures within 12 months after total knee arthroplasty (TKA) can negatively affect the functional outcome and the quality of life for patients who have had TKA. This aim of this study is to investigate (1) the incidence of hip fracture within 12 months after TKA and (2) the influence of hip fracture after TKA on functional outcome and quality of life in patients.

METHODS

Between March 1999 and February 2012, 25 patients who sustained an ipsilateral hip fracture within 12 months after TKA were included in this study. A propensity score matching algorithm was used to select a 1:3 control group without hip fracture. All patients were assessed using the Oxford Knee Score (OKS), Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Physical Component Score (PCS) and Mental Component Score (MCS) of SF-36®.

RESULTS

The incidence of hip fracture was 0.16% among male patients and 0.20% for female patients. At 24 months after TKA, the OKS was 36 ± 7 in the hip fracture group versus 41 ± 5 in the control group (p = 0.003). The KSFS was 50 ± 24 in the hip fracture group versus 68 ± 21 in the control group (p = 0.001), while the KSKS was 83 ± 12 and 87 ± 8, respectively (p = 0.166). The PCS was 37 ± 12 in the hip fracture group versus 47 ± 11 in the control group (p < 0.001), while the MCS was 55 ± 10 and 54 ± 11, respectively (p = 0.664).

CONCLUSION

Although hip fracture during the rehabilitation period after TKA is uncommon, these patients have poorer functional outcome and quality of life. We recommend additional caution against hip fracture after TKA.

CT-based TruMatch® Personal Solutions for knee replacement Surgery … Does it really match?

Objective

Patient-specific templates promises to be able to increase alignment while decreasing operative time, increasing patient throughput, decreasing instrumentation, reducing risk of fat embolism and intraoperative bleeding, decreasing tissue loss, shortening recovery, reducing post-operative pain and decreasing incidence of infection. However, multiple studies have shown conflicting results regarding these potential benefits. This study serves to critically evaluate the potential advantages and disadvantages of using a patient-specific templating technique through a single-surgeon study.

Methods

All patients who underwent primary total knee arthroplasty (TKA) for osteoarthritis of the knee using TruMatch® Personal Solutions total knee replacement by a single surgeon were identified. An age-, gender-, side-, diagnosis- and surgeon-matched cohort who underwent conventional primary TKAs was randomly identified for comparison.

Results

The average distal medial femur (p < 0.001), distal lateral femur (p < 0.001), posteromedial femur (p < 0.001), posterolateral femur (p < 0.001), medial tibial (p < 0.001) and lateral tibial (p = 0.12) predicted cuts showed significant difference from the actual corresponding cuts. Three knees also required the need to freehand. There was no significant difference in mechanical (p = 0.96) and anatomical alignments (p = 0.26), as well as the changes in mechanical (p = 0.06) and anatomical (p = 0.39) alignments between the two groups. Duration of surgery (p = 0.26), length of inpatient stay (p = 0.06) and incidence of wound infection (p = 1.00) were similar. Additionally, patients in the TruMatch® Personal Solutions group had a greater decrease drop in hemoglobin levels (p = 0.02), with five transfusions needed while only one patient in the conventional group required transfusion (p = 0.09).

Conclusion

Our early experience and results with the CT-based TruMatch® Personal Solutions templates for TKA has not been promising. Despite promised, there were no demonstrable benefits with the technology. Moreover, the disadvantage of having increased blood loss was identified. Further studies are required to recommend the use of this technology.

Increased constraint of rotating hinge knee prosthesis is associated with poorer clinical outcomes as compared to constrained condylar knee prosthesis in total knee arthroplasty

The aim of this study was to evaluate whether there are any differences in patient-reported outcome measures between semi-constrained condylar constrained knee (CCK) and fully constrained rotating hinge knee (RHK) prostheses in midterm follow-up. We reviewed prospectively collected data of our hospital arthroplasty registry between 2007 and 2014. Thirty-nine patients were identified to have RHK prosthesis TKA and matched for a number of primary/revision TKA, gender, age, body mass index and pre-operative clinical scores to a control group of 78 patients with CCK TKA. Patient demographics, range of movement, varus/valgus deformity, Short Form 36 (SF-36) scores, Oxford Knee Score (OKS), Knee Society Score (KSS) and patient satisfaction were evaluated. Pre-operatively, the RHK and the control group of CCK had similar demographics, proportion of primary/revision TKA and baseline clinical scores (p > 0.05). At 2-year follow-up, patients with CCK prostheses had significantly better clinical outcomes as compared to patients with RHK prosthesis in terms of KSS functional scores, OKS, SF-36 sub-domains of physical functioning, physical role functioning and physical component score. We conclude that at midterm follow-up of 2 years, the CCK patients as compared to RHK patients reported better clinical and functional outcomes in terms of OKS, KSS functional score and SF-36 with a greater proportion of patients who were satisfied and had their expectations met by surgery. Further biomechanical studies are needed to investigate the association between component constraint and clinical outcomes for these prostheses.

Clinical outcomes and patient satisfaction following revision of failed unicompartmental knee arthroplasty to total knee arthroplasty are as good as a primary total knee arthroplasty

BACKGROUND

With unicompartmental knee arthroplasty (UKA) being increasingly performed for medial compartment osteoarthritis (OA) of the knee, revision total knee arthroplasty (TKA) for failed UKA is expected to increase. Our primary aim is to evaluate patients in our tertiary institution who underwent revision of failed UKA to TKA to compare their pre-operative clinical scores (patient-reported outcome measures, PROMs) to those of primary TKA.

METHODS

Retrospective review of our institutional arthroplasty registry between 2001 and 2014 was performed. We identified 70 patients who underwent revision of UKA to TKA. The revision UKA to TKA patients was matched with 140 patients who underwent primary TKA for OA in terms of preoperative demographics, gender, age at time of surgery, body mass index (BMI), primary surgeon, and PROMs. Intra-operative data and postoperative complications or re-revision surgeries performed were reviewed.

RESULTS

In the revision UKA to TKA group, more stems, augments or constrained implants were used compared to primary TKA. A greater proportion of patients with metal-backed UKA revision to TKA required stems, augments or constrained implants as compared to all-polyethylene UKA revision to TKA, but not a significant proportion (P = 0.250). At two years postoperatively, there were no significant differences observed between the groups in terms of patient satisfaction and PROMs.

CONCLUSIONS

This study showed similar outcomes following revision of failed UKA to TKA and primary TKA. There were significant improvements in PROMs for revision UKA to TKA, which is comparable to that of primary TKA.

The safest and most efficacious route of tranexamic acid administration in total joint arthroplasty: A systematic review and network meta-analysis

INTRODUCTION

Blood loss in Total Joint Arthroplasty can be significant and often under-estimated. This study aims to investigate the safety and efficacy of different routes of tranexamic acid (TXA) administration in reducing blood transfusion after Total Hip Arthroplasty (THA) and Total Knee Arthroplasty (TKA). The secondary aim is to find the safest and most efficacious route and dose of TXA.

MATERIAL AND METHODS

PubMed, Embase, Cochrane library, China National Knowledge Infrastructure, and OpenGrey were systemically searched for randomised controlled trials investigating the efficacy and/or safety of TXA for THA and/or TKA. Network meta-analysis, comparing the number of transfusion and deep vein thrombosis (DVT) among different interventions, was performed using a multivariate meta-regression model with random-effects, adopting a frequentist approach.

RESULTS

211 publications (20,639 individuals) were included. For outcome of transfusion, all interventions showed significantly lower transfusion rates compared to placebo. When compared to placebo, TXA via intra-venous and topical showed statistically significant lowest risk ratio (RR = 0.11, 95CI: 0.03, 0.41). For safety, TXA via topical showed relatively lowest risk ratio (RR = 0.75, 95CI 0.44, 1.30). TXA via topical and intra-articular had the highest but statistically insignificant RR (RR = 1.10, 95%CI: 0.51, 2.38). Therefore, current studies did not reveal any significant safety issue in using TXA.

CONCLUSION

All forms of TXA administration showed significantly lower transfusion rate compared to control. There is a trend towards better efficacy with intra-venous and topical. In patients with higher risk of thrombosis, physicians may consider topical alone for its best safety profile.

No Difference in Functional Outcomes after Total Knee Arthroplasty with or without Pinless Navigation

This study aims to investigate the functional outcomes of pinless navigation (BrainLAB VectorVision Knee 2.5 navigation system; Munich, Germany) as an intraoperative alignment guide in total knee arthroplasty (TKA). A prospective, 24-month follow-up study of 100 patients who were scheduled and randomized into two groups, the pinless navigation and conventional surgery, was conducted. All TKAs were performed with the surgical aim of achieving neutral coronal alignment with the 180-degree mechanical axis. The outcomes measured in this study were Oxford Knee Score (OKS), Knee Society Score (KSS), Short Form-36 (SF-36), and range of motion (ROM). At 24-month postoperatively, four and two patients were lost to follow-up from the pinless navigation group and conventional group, respectively. There were no significant differences in absolute scores of the OKS, KSS, and ROM, as well as changes from preoperative baseline, between pinless navigation and conventional groups at both 6 and 24 months postoperatively. Pinless navigation results in comparable functional outcomes as conventional TKA at 6 and 24 months postoperatively.

The influence of obesity on functional outcome and quality of life after total knee arthroplasty: a ten-year follow-up study

Aims

This study investigated the influence of body mass index (BMI) on patients' function and quality of life ten years after total knee arthroplasty (TKA).

Patients and Methods

A total of 126 patients who underwent unilateral TKA in 2006 were prospectively included in this retrospective study. They were categorized into two groups based on BMI: < 30 kg/m² (control) and ≥ 30 kg/m² (obese). Functional outcome was assessed using the Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), and Oxford Knee Score (OKS). Quality of life was assessed using the Physical (PCS) and Mental Component Scores (MCS) of the 36-Item Short-Form Health Survey.

Results

Results Patients in the obese group underwent TKA at a younger age (mean, 63.0 years, sd 8.0) compared with the control group (mean, 65.6 years, sd 7.6; p = 0.03). Preoperatively, both groups had comparable functional and quality-of-life scores. Ten years postoperatively, the control group had significantly higher OKS and MCS compared with the obese group (OKS, mean 18 (sd 5) vs mean 22 (sd 10), p = 0.03; MCS, mean 56 (sd 10) vs mean 50 (sd 11), p = 0.01). After applying multiple linear regression with the various outcomes scores as dependent variables and age, gender, and Charlson Comorbidity Index as independent variables, there was a clear association between obesity and poorer outcome in KSFS, OKS, and MCS at ten years postoperatively (p < 0.01 in both KSFS and OKS, and p = 0.03 in MCS). Both groups had a high satisfaction rate (97.8% in the control group vs 87.9% in the obese group, p = 0.11) and fulfillment of expectations at ten years (98.9% in the control group vs 100% in the obese group, p = 0.32).

Conclusion

Although both obese and non-obese patients have significant improvements in function and quality of life postoperatively, obese patients tend to have smaller improvements in the OKS and MCS ten years postoperatively. It is important to counsel patients on the importance of weight management to achieve a more sustained outcome after TKA. Cite this article: Bone Joint J 2018;100-B:579-83.

Change in Body Mass Index After Total Knee Arthroplasty and Its Influence on Functional Outcome

BACKGROUND

There is often an assumption by patients that weight loss will occur once their knee pain is relieved by total knee arthroplasty (TKA). This study aims to evaluate (1) the change in patients' body mass index (BMI) after TKA; (2) if postoperative change in BMI influences functional outcome and survival rate of TKA; and (3) the predictive factors associated with change in BMI.

METHODS

Seven thousand seven hundred thirty-three patients who underwent a primary TKA between 2001 and 2010 were included in this study. Functional outcome scores collected at 2 years after surgery include the Oxford Knee Score, Knee Society Function Score, Knee Society Knee Score, Physical Component Score, and Mental Component Score of short form 36.

RESULTS

Among these patients, 1067 (14%) had reduction in BMI, 5045 (65%) maintained their BMI, and 1621 (21%) had gain in BMI. The differences in improvement in Oxford Knee Score, Knee Society Function Score, Knee Society Knee Score, and Physical Component Score among the 3 groups of patients were less than the known minimal clinically important difference of these scores. The 10-year survival rate of TKA was not influenced by patients' change in BMI after surgery (P = .435). Obese class I, II, and III patients were more likely to reduce their BMI after TKA than those with normal preoperative BMI (P = .002, P = .012, and P = .004, respectively), while older patients were less likely to have gain in BMI after surgery (P = .001).

CONCLUSION

A change in BMI after TKA did not influence the functional outcome clinically or the survival rate of the TKA implant.

Comparison of outcome measures from different pathways following total knee arthroplasty

INTRODUCTION

The benefits of extended inpatient rehabilitation following total knee arthroplasty (TKA) in local community hospitals (CHs) are unproven. Our study compared functional outcomes between patients discharged home and to CHs following TKA.

METHODS

A case-control study was conducted of patients undergoing primary unilateral TKA. Consecutive patients (n = 1,065) were retrospectively reviewed using the Knee Society Clinical Rating System (KSCRS), 36-item Short Form Health Survey (SF-36) and Oxford Knee Score (OKS) preoperatively, and at the six-month and two-year follow-ups.

RESULTS

Overall, 967 (90.8%) patients were discharged home and 98 (9.2%) to CHs. CH patients were older (mean age 70.7 vs. 67.2 years; p < 0.0001), female (86.7% vs. 77.5%; p = 0.0388) and less educated (primary education and above: 61.7% vs. 73.8%; p = 0.0081). Median CH length of stay was 23.0 (range 17.0-32.0) days. Significant predictors of discharge destination were older age, female gender, lower education, and poorer ambulatory status and physical health. Preoperatively, CH patients had worse KSCRS Function (49.2 ± 19.5 vs. 54.4 ± 16.8; p = 0.0201), SF-36 Physical Functioning (34.3 ± 22.6 vs. 40.4 ± 22.2; p = 0.0017) and Social Functioning (48.2 ± 35.1 vs. 56.0 ± 35.6; p = 0.0447) scores. CH patients had less improvement for all scores at all follow-ups. Regardless of preoperative confounders, with repeated analysis of variance, discharge destination was significantly associated with KSCRS, SF-36 and OKS scores.

CONCLUSION

Older, female and less educated patients with poorer preoperative functional scores were more likely to be discharged to CHs after TKA. At the two-year follow-up, patients in CHs had less improvement in functional outcomes than those discharged home.

THINK surgical TSolution-One® (Robodoc) total knee arthroplasty

THINK Surgical TSolution-One^® is an active-autonomous, image-based, robotic milling system which enables the surgeon to attain a consistently accurate implant component positioning. The TSolution-One^® system is capable of achieving this through an image-based preoperative planning system which allows the surgeon to create, view and analyse the surgical outcome in 3D. The accuracy and precision of component positioning have been attributed to the following factors: customized distal femoral resection, accurate determination of the femoral rotational alignment, minimization of errors and maintenance of bone temperature with robotic milling. Despite all these advantages, there is still a paucity of long-term, high-quality data that demonstrates the efficacy of robotic-assisted total knee arthroplasty (TKA). Questions regarding radiation risks, prolonged surgical duration and cost-effectiveness remain unanswered. This paper aims to describe: (1) TSolution-One^® surgical technique; (2) limitations and complications; (3) clinical and radiological outcomes.

Identifying an Ideal Time Frame for Staged Bilateral Total Knee Arthroplasty to Maximize Functional Outcome

Compared with staged bilateral total knee arthroplasty (TKA), simultaneous bilateral TKA carries a higher risk of cardiac complications, pulmonary complications, and mortality, especially in patients with preexisting cardiopulmonary disease or advanced age. However, the period of time between staged TKAs that would eliminate these increased risks has yet to be determined. The purpose of this study is to evaluate complication rates and functional outcome in patients who underwent staged bilateral TKA and to determine an optimal time frame for the second knee. The authors retrospectively reviewed 306 patients who underwent staged bilateral TKA between 2002 and 2013. Patients were grouped into 31 to 90, 91 to 180, 181 to 270, and 271 to 365 days interval, where complication and 90-day readmission rates for the second TKA were identified. Patients were also assessed preoperatively and 2 years postoperatively using the Oxford knee score (OKS) and Short-Form (SF)-36. There was no significant difference in complication and 90-day readmission rates between the various groups. The functional outcome of the knees scored 2 years postoperatively using OKS and SF-36 showed comparable results across all four groups. Thus, the authors could not identify an ideal time frame for performing the second TKA with the objective of maximizing functional outcome.

The accuracy of a hand-held navigation system in total knee arthroplasty

INTRODUCTION

This study aims to evaluate the effectiveness of a new hand-held navigation system. The authors of this study hypothesize that this navigation system will improve overall lower limb alignment and implant placement without causing a delay in surgery.

PATIENTS AND METHODS

Two hundred consecutive patients diagnosed with tricompartmental osteoarthritis and underwent total knee arthroplasty by a senior surgeon were included in this study. One hundred patients underwent TKA using the hand-held navigation system, while the other 100 patients underwent TKA using the conventional technique. The primary outcomes of this study were the overall alignment of the lower limb and the position of the components. This was determined radiologically using the: (1) Hip-Knee-Ankle angle (HKA) for lower limb alignment; (2) Coronal Femoral-Component angle (CFA); and (3) Coronal Tibia-Component angle (CTA) for component position. Normal alignment was taken as 180° ± 3° for the HKA and 90° ± 3° for both the CFA and CTA.

RESULTS

For the CFA, the proportion of outliers was 7 and 17% in the hand-held navigation and conventional group, respectively (p = 0.030). For the HKA and CTA, there was no difference in the proportion of outliers between the two groups. The duration of surgery was 73 ± 9 min and 87 ± 15 min in the hand-held navigation and conventional group, respectively (p < 0.001).

CONCLUSION

This hand-held navigation system is an effective intraoperative tool for reducing the proportion of outliers for femoral implant placement as well as the duration of surgery. The authors conclude that it can be considered for use to check femoral implant placement intra-operatively.

LEVEL OF EVIDENCE

III.

The influence of body mass index on functional outcome and quality of life after total knee arthroplasty

AIMS

This study investigated the influence of body mass index (BMI) on the post-operative fall in the level of haemoglobin (Hb), length of hospital stay (LOS), 30-day re-admission rate, functional outcome and quality of life, two years after total knee arthroplasty (TKA).

PATIENTS AND METHODS

A total of 7733 patients who underwent unilateral primary TKA between 2001 and 2010 were included. The mean age was 67 years (30 to 90). There were 1421 males and 6312 females. The patients were categorised into three groups: BMI < 25.0 kg/m(2) (normal); BMI between 25.0 and 39.9 kg/m(2) (obese); and BMI ≥ 40.0 kg/m(2) (morbidly obese).

RESULTS

Compared with the normal and obese groups, the mean LOS was longer by one day (95% confidence interval (CI) 0 to 2) in the morbidly obese group (p = 0.003 and p = 0.001 respectively). The 30-day re-admisison rate was also higher in the morbidly obese group compared to the obese group (OR 2.323, 95% CI 1.101 to 4.900, p = 0.024); and showed a higher trend compared to the normal group (OR 1.850, 95% CI 0.893 to 3.831, p = 0.100). However, the morbidly obese group had a smaller drop in post-operative Hb level by a mean of 0.5 g/dl (0.3 to 0.6) and 0.3 g/dl (0.1 to 0.5), when compared with the normal and obese groups respectively (both p < 0.001). Furthermore, the mean improvement in Oxford Knee Score (OKS) and Knee Society Knee Score (KSKS) at two years follow-up was three points (two to four) and five points (two to seven) more in the morbidly obese group than in the normal group (both p < 0.001). The mean improvement in Knee Society Function Score, and Physical and Mental Component Scores of Short Form-36 were comparable between the three BMI groups (p = 0.736, p = 0.739 and p = 0.731 respectively). The ten-year rate of survival was 98.8% (98.0 to 99.3), 98.9% (98.5 to 99.2) and 98.0% (95.8 to 100), for the normal, obese and morbidly obese groups, respectively (p = 0.703).

CONCLUSION

Although morbidly obese patients have a longer LOS and higher 30-day re-admission rate after TKA, they have a smaller drop in post-operative Hb level and larger improvement in OKS and KSKS at two years follow-up. The ten-year rate of survival of TKA was also comparable with those with a normal BMI.

TAKE HOME MESSAGE

Morbidly obese patients should not be excluded from the benefits of TKA. Cite this article: Bone Joint J 2016;98-B:780-5.

Acetabular Prosthetic Protrusio after Bipolar Hemi-Arthroplasty of the Hip: Case Report and Review of the literature

Introduction:

Bipolar hemi-arthroplasty of the hip is a commonly performed procedure in elderly patients with intra-capsular fracture of the neck of the femur with good short-term results for pain relief, return to activity and morbidity. The incidence of intra-pelvic prosthesis migration or protrusion is rare and one of the inciting factors is chronic low-grade sepsis. Acetabular prosthesis protrusion poses a difficult and challenging surgical problem due to surrounding neurovascular structures.

Case Presentation:

We present a case report of 60-year-old Chinese female suffering from chronic sepsis of the hip joint causing acetabular prosthetic protrusion with a concomitant peri-prosthetic femoral shaft fracture secondary to a fall, 5 years post index surgery of bipolar hemiarthroplasty for an intra-capsular neck of femur fracture. This patient subsequently underwent a two-stage revision total hip arthroplasty. We aim to discuss the diagnostic approach and surgical management of this complex case of infected protruded bipolar hip hemi-arthroplasty.

Conclusion:

We highlight three recommendations from this clinical experience. Firstly, there should be a high index of suspicion for chronic infection in protruded prostheses following low energy trauma. Secondly, pre-operative planning for infected protruded prosthetic hips is essential, including arteriogram and a two-staged procedure to tackle possible soft tissue complications. Thirdly, the combined use of serological markers, fluid aspiration as well as intra-operative frozen section is important in the management of PJI and to confirm bacterial eradication before re-implantation.

Outcomes of Total Knee Arthroplasty in Patients With Poliomyelitis

BACKGROUND

We report our experience with outcomes of poliomyelitis in the Asian population.

METHODS

Sixteen total knee replacements in 14 patients with polio-affected knees were followed up for at least 18 months. Follow-up assessment included scoring with the American Knee Society Score (AKSS), Oxford knee score, and Short Form 36 Health Survey scores.

RESULTS

The mean AKSS improved from 25.59 preoperatively to 82.94 at 24 months, with greater improvement in the knee score. The mean Oxford knee score improved from 40.82 preoperatively to 20.53 at 24 months. The mean AKSS pain score rose from 2.35 to 47.66 at 24 months. The Short Form 36 Health Survey physical functioning and bodily pain scores improved for all patients.

CONCLUSION

Primary total knee arthroplasty of poliomyelitis-affected limbs shows good outcomes, improving quality of life, and decreasing pain.

Oral health of Hong Kong children: a historical and epidemiological perspective

OBJECTIVE

To provide a historical and epidemiological overview of the oral health of Hong Kong children.

METHODS

Literature published before 2014 related to the oral health of Hong Kong children, supplemented with information accessed from government-archived oral health reports, was sourced using electronic databases and hand searches. Dental caries experience, periodontal health, enamel defects, and malocclusion of Hong Kong children were reviewed.

RESULTS

A decline in the prevalence and extent of dental caries was observed among Hong Kong schoolchildren and adolescents after the 1960s. Among preschool children, however, dental caries remains common and the extent appears to have increased. The periodontal health of Hong Kong children remains unsatisfactory. Recently, enamel defects/dental fluorosis have considerably reduced. Information about malocclusion in Hong Kong children is limited.

CONCLUSIONS

Since the 1960s, following public health policies, health promotion activities, and the introduction of a School Dental Care Service, improvements in the oral health of schoolchildren are evident. Nonetheless, the oral health of preschool children remains a concern. Policies and practices to improve the oral health of preschool children in Hong Kong are required.

Low Infection Rates in Total Knee Arthroplasty in End Stage Renal Failure Patients

End stage renal failure is considered a risk factor for postoperative infection and many surgeons are cautious in offering this group of patients total knee arthroplasty for symptomatic osteoarthritis. In this retrospective study, 16 total knee arthroplasties were performed in 13 patients and each case was followed up for an average of 5.1 years. We report no cases of infection and also an overall improvement in multiple validated outcome measures. There were, however, 2 cases of periprosthetic loosening. As the patients in our series were generally younger and none was diagnosed with stroke or peripheral vascular disease at the time of surgery, we believe that careful patient selection is key to reducing infection rates in this challenging group of patients.

Intravenous versus intra-articular tranexamic acid in total knee arthroplasty: A double-blinded randomised controlled noninferiority trial

BACKGROUND

Despite the proven efficacy of both intravenous (IV) and intra-articular (IA) tranexamic acid (TXA) in reducing blood loss during total knee arthroplasty (TKA), the ideal route of administration remained debatable. This study aimed to compare the effect of IV versus IA TXA on transfusion incidences, perioperative blood loss and postoperative lower limb swelling during TKA.

METHODS

One hundred patients were prospectively randomised into two groups: 1) IV TXA; and 2) IA TXA. In both groups, TXA was administered intraoperatively after cementing the prostheses. The perioperative blood loss was calculated using the haemoglobin balance method. The thigh, suprapatellar, and calf girths were measured preoperatively and on postoperative day (POD) 4.

RESULTS

Two patients in the IV group and one patient in the IA group required blood transfusion (p=0.500). The median and interquartile range (IQR) of perioperative blood loss on POD1 and POD4 was 530 (IQR 386,704) and 730 (IQR 523,925) ml for the IV group, compared with 613 (IQR 506,703) and 799 (IQR 563,1067) ml for the IA group (p=0.090 and p=0.232 respectively). The median increment in thigh, suprapatellar, and calf girths were 1.5 (IQR 0, 3.0), 2.0 (IQR 0.5, 4.0) and 0 (IQR 0, 1.0) cm for the IV group, compared to 2.0 (IQR 1.0, 4.0), 2.0 (IQR 0, 4.5) and 0 (IQR 0, 1.5) cm for the IA group (p=0.246, p=0.562, and p=0.937 respectively).

CONCLUSIONS

Both IV and IA TXA had comparable effect on transfusion incidences, perioperative blood loss, and postoperative lower limb swelling during TKA. IA TXA is an alternative to IV TXA.

LEVEL OF EVIDENCE

I.

Cruciate retaining versus posterior stabilized total knee arthroplasty after previous high tibial osteotomy

PURPOSE

This study aimed to investigate the clinical outcome of total knee arthroplasty (TKA) after previous high tibial osteotomy (HTO) using cruciate retaining (CR) versus posterior stabilized (PS) prostheses.

METHODS

Between 2001 and 2010, 133 patients who underwent TKA after previous HTO were included in this study and prospectively followed up for two years. Two independent assessors recorded the range of motion of the operated knee, anterior-posterior (AP) laxity, medial-lateral (ML) laxity, Oxford Knee Score (OKS), Knee Society Function Score (KSFS) and Knee Society Knee Score (KSKS).

RESULTS

Thirty-three patients received CR prostheses, while 100 patients received PS prostheses. The median (inter-quartile range) knee flexion at 6 months and 2 years post-TKA was 101° (90, 116) and 110° (90, 118), respectively for the CR group, compared to 115° (100, 121) and 118° (108, 125) for the PS group (p = 0.010 and p = 0.009, respectively). AP and ML laxities were comparable in both groups of patients. While both groups of patients showed improvement in OKS, KSFS and KSKS at 6 months and 2 years post-TKA, there was no significant difference in these clinical scores between the two groups at both time points of follow-up. None of the 133 patients required revision surgery.

CONCLUSIONS

Although PS prostheses offer better knee flexion in TKA after previous HTO, the knee stability, clinical scores and revision rate at 6 months and 2 years post-TKA are comparable between CR and PS prostheses. The authors conclude that CR is an alternative to PS prostheses in patients undergoing TKA after previous HTO.

LEVEL OF EVIDENCE

III.

Spontaneous disruption of the bilateral knee extensor mechanism: a report of two cases

Spontaneous disruption of the knee extensor mechanism is associated with systemic diseases, steroid usage, and repeated microtrauma. Early repair or reconstruction is imperative for optimal outcome. We report 2 cases of spontaneous disruption of the bilateral knee extensor mechanism. The first patient had connective tissue disease and long-term steroid use. She had acute-on-chronic spontaneous bilateral patellar tendon rupture. She underwent reconstruction with an allograft and defunctioning wire. The second patient had end-stage renal failure with tertiary hyperparathyroidism and was on haemodialysis. He had a right patellar tendon rupture and a left quadriceps tendon rupture. He underwent primary repair of both tendons. Postoperatively, both patients followed a strict physiotherapy regimen and achieved good functional outcome.

Computer navigation is a useful intra-operative tool for joint line measurement in total knee arthroplasty

BACKGROUND

Restoration of the native joint line in total knee arthroplasty is important in restoring ligamentous balance and normal knee kinematics. Failure to achieve this could lead suboptimal outcomes. The purpose of this study was to analyze the clinical and functional outcome of patients who demonstrated joint line changes after computer-assisted (CAS) total knee arthroplasty (TKA).

METHODS

One hundred sixty-eight patients (168 knees) underwent CAS TKA by two surgeons at a single institution with 2 years follow-up. The final change in joint line was calculated from the verified tibial resection and distal femoral cuts. Group A patients had joint line changes of less than 4mm and Group B patients had joint line changes of more than 4mm. Post-operative Oxford scores, Knee scores, Function scores and SF-36 scores were obtained at 6 months and 2 years post TKA.

RESULTS

There was significant linear correlation between joint line changes and Oxford scores (P=0.0001), Function scores (P=0.0001) and Knee scores (P=0.0001) at 6 months and Oxford scores (P=0.0001) alone at 2 years with increasing joint line changes having poorer outcome scores. Group A compared to Group B patients demonstrated better Oxford scores (P=0.0001), Function scores (P=0.0001), Knee scores (P=0.0001) and total SF-36 scores (P=0.003) at 6 months as well as better Oxford scores (P=0.0001) and Knee scores (P=0.014) at 2 years.

CONCLUSIONS

CAS is a useful intra-operative tool for assessing the final joint line in TKA. Outliers in joint line changes of ≥4 mm are associated with poorer clinical outcome scores.

LEVEL OF EVIDENCE

Prognostic Study, Level II-1.

Evaluation of the relationship between anteroposterior translation of a posterior cruciate ligament-retaining total knee replacement and functional outcome

The success of total knee replacement (TKR) depends on optimal soft-tissue balancing, among many other factors. The objective of this study is to correlate post-operative anteroposterior (AP) translation of a posterior cruciate ligament-retaining TKR with clinical outcome at two years. In total 100 patients were divided into three groups based on their AP translation as measured by the KT-1000 arthrometer. Group 1 patients had AP translation < 5 mm, Group 2 had AP translation from 5 mm to 10 mm, and Group 3 had AP translation > 10 mm. Outcome assessment included range of movement of the knee, the presence of flexion contractures, hyperextension, knee mechanical axes and functional outcome using the Knee Society score, Oxford knee score and the Short-Form 36 questionnaire. At two years, patients in Group 2 reported significantly better Oxford knee scores than the other groups (p = 0.045). A positive correlation between range of movement and AP translation was noted, with patients in group 3 having the greatest range of movement (mean flexion: 117.9° (106° to 130°)) (p < 0.001). However, significantly more patients in Group 3 developed hyperextension > 10° (p = 0.01). In this study, the best outcome for cruciate-ligament retaining TKR was achieved in patients with an AP translation of 5 mm to 10 mm.

Fibrolipoma of multiple nerves in the wrist

We report fibrolipoma involving the median nerve, its palmar cutaneous branch as well as the ulnar nerve in the same hand of a 25-year-old woman. The patient presented with a lump in the wrist with signs of carpal tunnel syndrome. Multiple nerve involvement was detected on magnetic resonance imaging and further confirmed at surgical exploration and decompression. Imaging is recommended in the management of an unusual lump in the wrist.