Is discharge knee range of motion a useful and relevant clinical indicator after total knee replacement? Part 1

Arthrofibrosis after total knee arthroplasty: patients with keloids at risk

BACKGROUND

Arthrofibrosis remains one of the leading causes for revision in primary total knee arthroplasty (TKA). Similar in nature to arthrofibrosis, hypertrophic scars and keloid formation are a result of excessive collagen formation. There is paucity in the literature on whether there is an association between keloid formation and the development of arthrofibrosis following TKA. Therefore, the purpose of this study was to utilize a large nationwide database to identify and compare the rates of postoperative complications related to arthrofibrosis after primary TKA in patients with history of hypertrophic scar and keloid disorders versus those without.

METHODS

Patient records from 2010 to the second quarter of 2016 were queried from an administrative claims database, comparing rates of arthrofibrosis, manipulation under anesthesia (MUA), lysis of adhesions (LOA), and revision TKA in patients with chart diagnosis of keloids versus those without in patients who underwent primary TKA. Data analysis was performed using R statistical software (R Project for Statistical Computing, Vienna, Austria) utilizing multivariate logistic regression, chi square analysis, or Welch's t- test where appropriate with p values < 0.05 being considered statistically significant.

RESULTS

Of 545,875 primary TKAs, 11,461 (2.1%) had a keloid diagnosis at any time point in their record, while 534,414 (97.9%) had not. Patients in the keloid cohort had a significantly higher association with ankylosis within 30 days (OR, 1.7), 90 days (OR, 1.2), 6 months (OR, 1.2), and 1 year (OR, 1.3) following primary TKA. The keloid cohort also had a significantly greater risk of MUA (90-day OR, 1.1; 6-month OR, 1.1; 1-year OR, 1.2) and LOA (90-day OR, 2.2; 6-month OR, 2.0; 1-year OR, 1.9).

CONCLUSION

Patients with keloids have increased odds risk of arthrofibrosis following primary TKA. These patients are subsequently at a higher odds risk of undergoing the procedures necessary to treat arthrofibrosis, such as MUA and LOA. Future studies investigating confounding factors such as race, prior surgery, range of motion, and postoperative recovery are needed to confirm the association of keloid diagnosis and arthrofibrosis following primary TKA demonstrated in this study.

LEVEL OF EVIDENCE

Level III retrospective comparative study.

The risk of manipulation under anesthesia due to unsatisfactory knee flexion after fast-track total knee arthroplasty

BACKGROUND

Fast-track TKA has significantly shortened the time available for physiotherapists to optimize knee ROM before discharge. Safety aspects concerning knee stiffness and the need for manipulation in a fast-track setting need to be illuminated. The study aims were to analyze if fast-track TKA can be considered safe considering rates of knee manipulation and if there is an association between knee ROM at time of discharge and the need for later manipulation.

METHODS

Primary TKAs operated in 2011 at our institution were eligible for inclusion. The study group consisted of 359 TKAs.

RESULTS

Manipulation of the knee was performed in 21 of 359 TKAs (5.8%). Seventy-one percent were discharged with a flexion ≥70° combined with an extension deficit of ≤10°. The occurrence of MUA for these patients was 4.3%. The prevalence of knee manipulation showed a statistically significant association with the achieved knee flexion at discharge (p=0.02). Median length of stay was two days.

CONCLUSION

Compared with literature findings fast-track TKA surgery may be considered safe based on the acceptable rate of knee manipulations after TKA (5.8%). We suggest ROM of ≥70° flexion combined with an extension deficit of ≤10° as an "optimal-zone" for ROM at discharge. The reason for this is the low occurrence of MUA (4.3%) in relation to the large amount of TKAs it represents (71%). The indication for MUA is multifactorial and ROM at discharge serves only as an indicator of later MUA risk.

Traditions and myths in hip and knee arthroplasty

BACKGROUND AND PURPOSE

Traditions are passed on from experienced surgeons to younger fellows and become "the right way to do it". Traditions associated with arthroplasty surgery may, however, not be evidence-based and may be potentially deleterious to both patients and society, increasing morbidity and mortality, slowing early functional recovery, and increasing cost.

METHODS

We identified selected traditions and performed a literature search using relevant search criteria (June 2014). We present a narrative review grading the studies according to evidence, and we suggest some lines of future research.

RESULTS

We present traditions and evaluate them against the published evidence. Preoperative removal of hair, urine testing for bacteria, use of plastic adhesive drapes intraoperatively, and prewarming of the operation room should be abandoned-as should use of a tourniquet, a space suit, a urinary catheter, and closure of the knee in extension. The safety and efficacy of tranexamic acid is supported by meta-analyses. Postoperatively, there is no evidence to support postponement of showering or postponement of changing of dressings to after 48 h. There is no evidence to recommend routine dental antibiotic prophylaxis, continuous passive motion (CPM), the use of compression stockings, cooling for pain control or reduction of swelling, flexion of at least 90 degrees as a discharge criterion following TKA, or having restrictions after THA. We present evidence supporting the use of NSAIDs, early mobilization, allowing early travel, and a low hemoglobin trigger for transfusion.

INTERPRETATION

Revision of traditions and myths surrounding hip and knee arthroplasty towards more contemporary evidence-based principles can be expected to improve early functional recovery, thus reducing morbidity, mortality, and costs.

Predicting functional performance and range of motion outcomes after total knee arthroplasty

OBJECTIVE

The aim of this study was to assess the predictive value of functional performance and range of motion measures on outcomes after total knee arthroplasty.

DESIGN

This is a secondary analysis of two pooled prospective randomized controlled trials. Sixty-four subjects (32 men and 32 women) with end-stage knee osteoarthritis scheduled to undergo primary total knee arthroplasty were enrolled. Active knee flexion and extension range of motion, Timed Up and Go (TUG) test time, and 6-min walk test distance were assessed.

RESULTS

Preoperative measures of knee flexion and extension were predictive of long-term flexion (β = 0.44, P < 0.001) and extension (β = 0.46, P < 0.001). Acute measures of knee flexion and extension were not predictive of long-term flexion (β = 0.09, P = 0.26) or extension (β = 0.04, P = 0.76). Preoperative TUG performance was predictive of long-term 6-min walk performance (β = -21, P < 0.001). Acute TUG performance was predictive of long-term functional performance on the 6-min walk test, after adjusting for the effects of sex and age (P = 0.02); however, once adjusted for preoperative TUG performance, acute TUG was no longer related to long-term 6-min walk performance (P = 0.65).

CONCLUSIONS

Acute postoperative measures of knee range of motion are of limited prognostic value, although preoperative measures have some prognostic value. However, acute measures of functional performance are of useful prognostic value, especially when preoperative functional performance data are unavailable.

The six-minute walk test is an excellent predictor of functional ambulation after total knee arthroplasty

BACKGROUND

The Six-minute walk (6 MW) and Timed-Up-and-Go (TUG) are short walk tests commonly used to evaluate functional recovery after total knee arthroplasty (TKA). However, little is known about walking capacity of TKA recipients over extended periods typical of everyday living and whether these short walk tests actually predict longer, more functional distances. Further, short walk tests only correlate moderately with patient-reported outcomes. The overarching aims of this study were to compare the performance of TKA recipients in an extended walk test to healthy age-matched controls and to determine the utility of this extended walk test as a research tool to evaluate longer term functional mobility in TKA recipients.

METHODS

The mobility of 32 TKA recipients one year post-surgery and 43 healthy age-matched controls were assessed using the TUG, 6 MW and 30-minute walk (30 MW) tests. The latter test was repeated one week later. Self-reported function was measured using the WOMAC Index and a physical activity questionnaire.

RESULTS

30 MW distance was significantly shorter amongst TKA recipients (mean 2108 m [95% CI 1837 to 2381 m]; Controls 3086 m [2981 to 3191 m], P < 0.001). Test-retest repeatability was high (ICC = 0.97, TKA; 0.96, Controls). Amongst TKA recipients, the 30 MW distance correlated strongly with the shorter tests (6 MW, r = 0.97, P < 0.001; TUG, r = -0.82, P < 0.001). Multiple regression modeling found 6 MW distance to be the only significant predictor (P < 0.001) of 30 MW distance, explaining 96% of the variability. The TUG test models were moderate predictors of WOMAC function (55%) and physical activity (36%) and were stronger predictors than 6 MW and 30 MW tests.

CONCLUSIONS

Though TKA recipients are able to walk for 30 minutes one year post-surgery, their performance falls significantly short of age-matched norms. The 30 MW test is strongly predicted by 6 MW test performance, thus providing strong construct validity for the use of the 6 MW test in the TKA population. Neither a short nor long walk test is a strong predictor of patient-reported function after TKA.