Trends in incidence and average waiting time for arthroplasty from 1998-2021: an observational study of 282,367 patients from the Scottish arthroplasty project

BACKGROUND

Current waiting times for arthroplasty are reported as being the worst on record. This is a combination of increasing demand, the COVID-19 pandemic and longer standing shortage of capacity. The Scottish Arthroplasty Project (SAP) is a National Audit that analyses all joint replacements undertaken in the Scottish NHS and Independent Sector. The aim of this study was to investigate the long-term trend in provision and waiting time for lower limb joint replacement surgery.

METHODS

All total hip replacements (THR) and total knee replacements (TKR) undertaken in NHS Scotland from 1998 to 2021 were identified. Waiting times data were analysed each year to determine the minimum, maximum, median, mean and standard deviation.

RESULTS

In 1998, there were 4,224 THR and 2,898 TKR with mean (range, SD) waiting time of 159.5 days (1-1,685, 119.8) and 182.9 days (1-1,946, 130.1). The minimum waiting times were both in 2013 for 7,612 THR - 78.8 days (0-539, 46) and 7,146 TKR - 79.1 days (0-489, 43.7). The maximum waiting times recorded were in 2021 with 4,070 THR waiting 283.7 days (0-945, 215) and 3,153 TKR waiting 316.8 days (4-1,064, 217).

CONCLUSIONS

This is the first robust large-scale national dataset showing trends in incidence and waiting time for THR and TKR over two decades. There was an expansion of activity with a reduction in waiting time, which peaked in 2013, followed by an increase in waiting time with a plateau and modest decline in the number of procedures.

Titanium Alloy Knee Implant Is Associated with Higher Bone Density over Cobalt Chromium: A Prospective Matched-Pair Case-Control Study

Background

Little is known about the relationship between implant material and periprosthetic bone mineral density (pBMD) in total knee arthroplasty (TKA). The purpose of this study was to investigate the change in pBMD after TKA and to compare pBMD changes between two different implant materials.

Methods

A prospective matched-pair case-control study was conducted on 29 patients who underwent bilateral TKAs. The participants were randomly allocated to undergo cemented TKAs with a titanium nitride (TiN)-coated implant on one knee (TiN group) and a cobalt-chromium (CoCr) implant on the other knee (CoCr group). The pBMD was measured using dual-energy X-ray absorptiometry scans before surgery and at 1 and 2 years after surgery. The results were then compared between the two groups. The pBMDs at longer follow-ups (> 2 years) were estimated using simple radiographs (pBMDe).

Results

At 2 years after surgery, the pBMD significantly decreased in both groups at medial metaphysis of the tibia and anterior portion of the distal femur (all p < 0.001). The CoCr group showed a larger decrease in pBMD than did the TiN group in the medial and anterior metaphysis of the proximal tibia (p = 0.003 and p = 0.046, respectively). The pBMDe was significantly higher in the TiN group at the anterior portion of the distal femur 7 years after surgery (p = 0.019).

Conclusions

The pBMD significantly decreased 2 years after TKA in certain regions regardless of the implant material used. However, the decrease was significantly less in the TiN group in specific regions of the tibia and femur. The TiN implant was beneficial in preserving the periprosthetic bone stock after TKA.

Blood transfusion and venous thromboembolism trends and risk factors in primary and aseptic revision total hip and knee arthroplasties: A nationwide investigation of 736,061 cases

BACKGROUND

Over the last years, new transfusion guidelines and pharmaceuticals have been introduced in primary and revision total hip and knee arthroplasty (P-THA, P-TKA, R-THA, R-TKA). In the US, a substantial decrease in transfusions has been observed in recent years. Little data exists on the subject in Europe. In this context we aimed to analyze: (1) Is there also a significant decrease in blood transfusion for these procedures in Germany? (2) Which patient and hospital related factors are associated with the risk of blood transfusion? (3) Is there a trend in complications, especially venous thromboembolism and stroke events that can be linked to tranexamic acid use?

HYPOTHESIS

There is a significant trend in decreasing blood transfusions in hip and knee arthroplasty.

METHODS

Using nationwide healthcare insurance data for inpatient hospital treatment, 736,061 cases treated between January 2011 and December 2017 were included (318,997 P-THAs, 43,780 R-THAs, 338,641 P-TKAs, 34,643 R-TKAs). Multivariable logistic regression was used to model the odds of transfusion as a function of the year of surgery. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated.

RESULTS

In each cohort the odds of transfusion decreased over time (2017 vs. 2011 (reference): P-THA: OR 0.42 (95%CI: 0.39-0.45), P-TKA: OR 0.41 (95%CI: 0.37-0.46), R-THA: OR 0.52 (95%CI: 0.47-0.58), R-TKA: OR 0.53 (95%CI: 0.46-0.61). Patient-related risk factors for blood transfusion included older age, female gender, lower Body Mass Index, comorbidities such as renal failure, cardiac arrhythmia, congestive heart failure, valvular disease, coagulopathy, depression, and antithrombotic medication prior to surgery. Venous thromboembolism or stroke events did not increase over the study period.

DISCUSSION

The incidence of blood transfusions in primary and revision TKA and THA decreased over the study period. This may be due to new transfusion guidelines and the introduction of novel pharmaceuticals such as tranexamic acid. A further improved patient blood management and a focus on vulnerable patient groups might lead to a further future reduction of transfusions, especially in R-THA.

LEVEL OF EVIDENCE

III; comparative observational study.

Optimal location of local anesthetic injection in the interspace between the popliteal artery and posterior capsule of the knee (iPACK) for posterior knee pain after total knee arthroplasty: an anatomical and clinical study

Background

This study aimed to determine the optimal location of local anesthetic injection in the interspace between the popliteal artery and posterior capsule of the knee (iPACK), using the anatomical pattern of the articular branch of tibial nerve (ABTN). We hypothesized that injection at the level of ABTN forming a popliteal plexus would mainly spread throughout the popliteal fossa without contacting the tibial or peroneal nerves.

Methods

The anatomical study included 30 soft cadavers. Ultrasound-guided dye injection was performed in legs of 10 cadavers after identifying the position of the ABTN and surrounding structures, followed by dissection to assess its spread. Clinical study was conducted in 15 patients undergoing total knee arthroplasty (TKA) with ultrasound-guided injection in the iPACK. All patients also received continuous adductor canal block. Sensorimotor function of the tibial and common peroneal nerves was determined.

Results

In the distal portion of the popliteal fossa, the tibial nerve and popliteal vessels ran superficially and closely together. The trajectory of ABTN ran lateral to the popliteal vasculature, forming a plexus towards the posterior capsule of the knee below the medial side of the upper edge of lateral femoral condyle. In cadavers, the ABTN and surrounding area of the popliteal plexus were stained with dye after injection. In the clinical study, no patients experienced complete motor or sensory blocks.

Conclusions

We described a modified iPACK technique injection at the level of the ABTN forming the popliteal plexus, and it may constitute an optional anesthetic regimen to promote early ambulation following TKA.

Three Concurrent Periprosthetic Joint Infections: A Case Report and Literature Review

Periprosthetic joint infections are a major cause of morbidity and mortality following total joint arthroplasty. Two-stage arthroplasty, with the use of an antibiotic cement spacer, is an effective means of managing periperiprosthetic joint infections. There is a lack of data relating to the management, prognosis, and clinical outcomes associated with multiple peri-prosthetic joint infections. Here, we present a case report of a patient successfully treated for three synchronic peri-prosthetic joint infections of both knees and a single hip.

The analgesic efficacy of the continuous adductor canal block compared to continuous intravenous fentanyl infusion with a single-shot adductor canal block in total knee arthroplasty: a randomized controlled trial

Background

The adductor canal block (ACB) is an effective intervention for postoperative analgesia following total knee arthroplasty (TKA). However, the ideal ACB regimen has not yet been established. We compared the analgesic effects between a continuous ACB group and fentanyl-based intravenous patient-controlled analgesia (IV-PCA) with a single-shot ACB group.

Methods

Patients who underwent TKA were randomly allocated to either a continuous ACB group (Group CACB) or IV-PCA with a single-shot ACB group (Group IVACB). Before the surgery, ultrasound guided ACB with 0.5% ropivacaine 20 cc was provided to all patients. Before skin incision, the infusion system (0.2% ropivacaine through an adductor canal catheter in group CACB vs. intravenous fentanyl in group IVACB) was connected. The postoperative pain severity; the side effects of local anesthetics and opioids; administration of rescue analgesics and anti-emetics; and sensorimotor deficits were measured.

Results

Postoperative pain severity was significantly higher in the IVACB group at 30 min, 4 h, 24 h, and 48 h after surgery. The averages and standard deviations (SD) of the NRS score of postoperative pain were 0.14 ± 0.37, 4.57 ± 2.37, 6.00 ± 1.63, and 4.28 ± 1.49, respectively in the IVACB group. Rescue analgesic requirements and quadriceps muscle strength were not statistically different between the groups throughout the postoperative period. Moreover, rescue antiemetic requirements were higher in group IVACB than group CACB.

Conclusions

In this study, the continuous ACB provided superior analgesia and fewer side effects without any significant motor deficit than the IV-PCA with a single-shot ACB.

Surgical site infection incidence and risk factors in knee arthroplasty: A 9-year prospective cohort study at a university teaching hospital in Spain

BACKGROUND

Surgical site infection (SSI) is one of the complications posed by knee replacement surgery. Hospital-based infection surveillance systems may provide indicators of improvement and allow the characterization of risk factors critical to reduce infection. The aims of this study were to compare the incidence of SSI in our center with rates in the Madrid Region, Spain, and the United States, and to evaluate any possible SSI-related risk factor in knee replacement surgery.

METHODS

All patients who underwent knee replacement surgery at a tertiary hospital in 2008-2016 were included. SSI was defined according to Centers for Disease Control and Prevention criteria. Infection rate was calculated. The association between risk factors and SSI incidence was assessed by reference to odds ratio (OR) with multivariate analysis.

RESULTS

The study population (n = 1969) had a global SSI risk of 1.0%. We found a declining trend in the follow-up period, from an SSI risk of 1.8% in 2009 to 0.4% in 2016. Independent risk factors included hair removal (OR: 3.09, 95% confidence interval [CI]: 1.27-7.50) and National Healthcare Safety Network risk index ≥ 2 (OR: 9.37, 95% CI: 2.90-30.26).

CONCLUSION

This study identified risk factors that showed the necessity to strictly comply with wound decontamination and patient preparation protocols, reduce surgery duration, and identify patients who require comprehensive monitoring.

Preoperative Serum Albumin Levels Predict Treatment Cost in Total Hip and Knee Arthroplasty

Background

Hypoalbuminemia (serum albumin < 3.5 g/dL) is associated with increased morbidity and mortality in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). However, costs associated with hypoalbuminemia remain unknown. This study investigated the effect of serum albumin on direct treatment costs, length of stay (LOS), and readmissions for primary and revision THA and TKA patients.

Methods

All adult patients at a single institution undergoing primary or revision THA or TKA between January 2014 and December 2016 were retrospectively reviewed. Patients were stratified by preoperative serum albumin level. The primary outcome was total direct costs at index hospitalization. Secondary outcomes included LOS and readmission within 30 days. Multivariable regressions were utilized to adjust for demographics and comorbidities.

Results

Of 3,785 patients, 114 (3.0%) had hypoalbuminemia. After adjustment, hypoalbuminemia was associated with a 16.2% increase in costs (β = 0.162; 95% confidence interval [CI], 0.112 to 0.213; p < 0.001), representing an average cost increase of $3,383 (95% CI, $2,281 to $4,485) relative to costs for serum albumin > 4.5 g/dL. The increased total costs were significantly higher in revision ($4,322, p = 0.034) than in primary ($3,446, p < 0.001) procedures. In adjusted regression, each 1.0 g/dL increase in serum albumin yielded a 6.6% reduction in costs (β = −0.066; 95% CI, −0.090 to −0.042]; p < 0.001), for average savings of $1,282 (95% CI, $759 to $1,806) per unit albumin. Adjusted regressions demonstrated that a 1-point increase in serum albumin reduced readmissions by 53% (odds ratio, 0.47; 95% CI, 0.31–0.73; p = 0.001) and LOS by 0.6 days (β = −0.60; 95% CI, −0.76 to −0.44; p < 0.001).

Conclusions

Hypoalbuminemia is associated with increased total direct costs, LOS, and readmissions following primary and revision THA and TKA. Future efforts to predict and address total costs should take into consideration the patient's preoperative serum albumin levels.

Blood level changes in total knee arthroplasty with and without a tourniquet

Objective

To evaluate the difference between the total blood loss in patients undergoing primary total knee arthroplasty with and without the use of tourniquet.

Methods

A retrospective cohort study, with analysis of medical records of patients undergoing primary total knee arthroplasty in 2015, with and without the use of a tourniquet. Comparison was performed of hemoglobin (HB) and hematocrit (HT) variation in the complete blood count (CBC) during the pre- and post-operative period between the two groups.

Results

There were 117 patients undergoing primary total knee arthroplasty included, minimum age of 33 and maximum of 86 years, with a mean of 67 years. 64.1% of the surgeries used a tourniquet and 35.9% did not. The mean preoperative HB in Group 1 was 13.08 and 12.97 in Group 2 (p = 0.435). The mean postoperative HB in Group 1 was 11.64 and 10.93 in Group 2 (p = 0.016). The variation of HB in Group 1 was 1.44 and 2.04 in Group 2 (p = 0.025). The mean preoperative HT in Group 1 was 38.96 and 39.01 in Group 2 (p = 0.898). The mean postoperative HT in Group 1 was 34.47 and 32.19 in Group 2 (p = 0.005). The variation of HT in Group 1 was 4.49 and 6.82 in Group 2 (p = 0.001). A total of 21 patients received transfusions RCC (red cell concentrates), as a result of HB below 8 g/dL or clinical symptoms, respectively, representing seven of Group 1 (9.3% of total intra-group) and 14 of Group 2 (33.3% of total intra-group), with p = 0.001.

Conclusion

In patients undergoing primary total knee arthroplasty using a tourniquet, a lower variance in the hematimetric indices was observed and fewer blood transfusions were necessary.

Effect of Preoperative Vitamin D Levels on Functional Performance after Total Knee Arthroplasty

Background

Low vitamin D levels affects muscle function. Vitamin D and calcium deficiency cause osteomalacic myopathy and poor functional recovery after hip fractures. The relationship of vitamin D and functional performance after total knee arthroplasty (TKA) is not previously reported.

Methods

Influence of vitamin D on functional performance before and after TKA was reviewed retrospectively in 120 patients. Of these, 64 had vitamin D deficiency (25-hydroxy vitamin D < 30 ng/mL) preoperatively. All 120 patients received vitamin D oral supplementation postoperatively. Functional parameters including Western Ontario and McMaster Osteoarthritis Index (WOMAC), Short-Form Health Survey questionnaire, and Knee Society Score were assessed pre- and postoperatively at 3 months.

Results

Preoperative function was significantly lower in osteoarthritic patients with vitamin D deficiency (WOMAC score; p = 0.040), but at 3 months all functional scores were similar.

Conclusions

We concluded that vitamin D deficiency has a negative effect on function in knee osteoarthritic patients. However, postoperative vitamin D supplementation can lead to functional recovery in these patients. Thus, TKA should not be delayed in vitamin D deficient patients; rather supplementation in the postoperative period is preferable to achieve comparable functional outcome at 3 months to patients with vitamin D sufficiency.

Comparison of alternate references for femoral rotation in female patients undergoing total knee arthroplasty

PURPOSE

Accurate rotational alignment of the femoral component is of vital importance for successful total knee arthroplasty (TKA). Two anatomical references located on the anterior femur were recently introduced. To determine which is more reliable reference axis for the femoral component rotation in female patients receiving TKA, the trochlear anterior line was compared with the femoral anterior tangent line.

MATERIALS AND METHODS

Preoperative computed tomography in 76 patients receiving TKA for varus deformity was performed, and the images were reconstructed into three-dimensional models. The trochlear anterior line was defined as the line connecting the most anterior portion of the lateral and medial femoral condyles and the femoral anterior tangent line as the line parallel to distal anterior femoral surface. The two angles between these reference axes and the surgical transepicondylar axis (TEA) in three-dimensional images (trochlear anterior line/TEA, femoral anterior tangent line/TEA) were measured. The correlation between these two angles was computed. We investigated to see whether a significant difference in variance existed.

RESULTS

The trochlear anterior line was internally rotated by 6.1° ± 2.5° with respect to TEA, whereas the femoral anterior tangent line by 9.5° ± 3.8°. The trochlear anterior line was externally rotated by 3.4° ± 3.3° with respect to the femoral anterior tangent line. There was a significant correlation between the trochlear anterior line/TEA and the femoral anterior tangent line/TEA.

CONCLUSIONS

The variance of the trochlear anterior line/TEA was significantly smaller than that of the femoral anterior tangent line/TEA demonstrating a more consistent distribution. When conventional reference axes such as the posterior condylar axis or the anteroposterior axis are unclear or differ, surgeons can rely on these alternative references. When trochlear anterior line and femoral anterior tangent line contradicts, the former might be more reliable for the rotational alignment of the femoral component in female patients.

LEVEL OF EVIDENCE

Case series with no comparison group, Level IV.

Cross-cultural adaptation and validation of the persian version of the oxford knee score in patients with knee osteoarthritis

BACKGROUND

The Oxford Knee Score (OKS) is a short patient-reported outcome instrument that measures pain and physical activity related to knee osteoarthritis. The purpose of this study is to evaluate, construct validity and consistent reliability of the Persian version of the OKS.

METHODS

The case series consisted of 80 patients who were clinically diagnosed with having knee osteoarthritis. All patients were requested to fill-in the Persian OKS and Short-Form 36 Health Survey (SF-36). Correlation analysis between the Persian versions of these two instruments was then carried out. The scores of the Persian SF-36 were used to evaluate convergent and divergent validity of the 12-item Persian OKS.

RESULTS

From a total of 80 patients, 63 were female (79%) and the remaining 17 were male (21%) with a mean age of 52.2 years. In the present study, high Cronbach's alpha of 0.95 confirms excellent internal consistency of the Persian OKS scale similar to previous investigations. The results confirm that the Persian version of this instrument is valid and reliable, similar to its English index and its subsequent translations in different languages.

CONCLUSION

The Persian OKS is a reliable instrument to evaluate knee function in patients with knee osteoarthritis and is a useful tool for outcome measurement in clinical research.

Plateau-patella angle in evaluation of patellar height in osteoarthritis

BACKGROUND

The plateau-patella angle (PPA), recently introduced as a new and simpler method of measuring patellar height from the lateral radiograph, has the advantage of simplicity over previously described methods as it involves a single angular measurement without the need for calculations. The purpose of this study was to validate the use of the PPA as a measurement for patellar height in knees with moderate to severe osteoarthritis.

METHODS

A total of 331 patients who underwent total knee arthroplasty at our institution with radiographs prior to surgery were evaluated. Of those, 297 (89.2%) were felt to be adequate for review. Three observers with different levels of orthopedic training measured PPA, Insall-Salvati, Caton-Deschamps, and Blackburne-Peel indices on a subset of 50 consecutive patients. Interobserver agreement for each of the four measurements was calculated and correlation between each of the measurements within each observer was calculated. The measurement of the PPA was repeated. Intraobserver agreement for the PPA was determined and a normal range and distribution was defined for this population.

RESULTS

For the three observers, the mean PPA for the entire cohort was 25.55, 25.31, and 24.42. The intraclass correlation coefficient (ICC) was 0.81, The ICC and intraobserver assessment were the highest for the PPA compared with the other ratios. The PPA was found to correlate most strongly with the Blackburne-Peel method.

CONCLUSIONS

The plateau-patella angle is a reliable way to evaluate patellar height in the osteoarthritic population. The measurement demonstrated a higher interobserver reliability compared with previously described methods.

LEVEL OF EVIDENCE

Retrospective Level IV.

Randomized controlled trial of the effectiveness of continuous passive motion after total knee replacement

OBJECTIVE

To determine the effects of using a continuous passive motion (CPM) device for individuals with poor range of motion (ROM) after a total knee replacement (TKR) admitted for postacute rehabilitation.

DESIGN

Randomized controlled trial.

SETTING

Inpatient rehabilitation facility (IRF).

PARTICIPANTS

Adults (N=141) after TKR with initial active knee flexion <75° on admission to the IRF.

INTERVENTION

Two randomized groups: group 1 (n=71) received the conventional 3 hours of therapy per day, and group 2 (n=70) received the addition of daily CPM use for 2 hours throughout their length of stay.

MAIN OUTCOME MEASURES

The primary outcome measure was active knee flexion ROM. Secondary outcome measures included active knee extension ROM length of stay, estimate of function using the FIM and Timed Up and Go test, girth measurement, and self-reported Western Ontario and McMaster Universities Osteoarthritis Index scores.

RESULTS

All subjects significantly improved from admission to discharge in all outcome measures. However, there were no statistically significant differences in any of the discharge outcome measures of the CPM group compared with the non-CPM group.

CONCLUSIONS

CPM does not provide an additional benefit over the conventional interventions used in an IRF for patient after TKR, specifically in patients with poor initial knee flexion ROM after surgery.