Rehabilitation complications following knee surgery

Interaction of gender and body composition on rectus femoris morphology as measured with musculoskeletal ultrasound imaging

Background:

Quadriceps function is an important measure in patients recovering postoperatively. Traditionally, strength measures that require high levels of resistance are contraindicated during the early postoperative phase. Thus it may be helpful to evaluate the utilization of other tools, such as ultrasound imaging, that allow for assessment during a position of low resistance.

Hypothesis:

The rectus femoris cross-sectional area (CSA) is affected by sex and body composition in healthy subjects.

Study Design:

Cross-sectional study.

Level of Evidence:

Level 4.

Methods:

Thirty-two healthy subjects (16 women, 16 men), selected from a previously larger study, were chosen for analysis. All subjects underwent a maximal volitional isometric contraction protocol from 0° to 90° of knee motion controlled by an isokinetic dynamometer. In the contracted and resting positions, the rectus femoris CSA was measured at each angle using ultrasound imaging. The contractile index (contracted − resting CSA) was calculated at each position. Subjects were separated into 1 of 4 groups based on sex and fat percentage (low or high). These data were analyzed using mixed-factor analysis of variance (group × angle) for each variable, with a critical α level of 0.05.

Results:

A significant interaction was noted for the CSA of the rectus femoris at rest (P < 0.03) and during contraction (P < 0.02). For both variables, all groups performed similarly, with the exception of women with high body fat percentage. No statistically significant interaction existed for the contractile index; however, a main effect for angle (P < 0.01) was observed.

Conclusion:

Rectus femoris CSA appears to depend on sex as well as the body composition of individuals.

Clinical Relevance:

Traditional subjective assessment measures of quadriceps strength and function have low reliability and functional validity. With the improved feasibility of ultrasound imaging in the clinical setting, quadriceps size may be more accurately measured during the early postoperative stages.

Wrist circumference is related to patellar tendon thickness in healthy men and women

The efficacy of dominant wrist circumference measurements to predict dominant lower extremity patellar tendon thickness at regions of interest for bone-patellar tendon-bone (BPTB) autograft harvest was studied among 24 healthy men and women. Dominant wrist circumference displayed good relationships with dominant lower extremity patellar tendon thickness as determined by two-dimensional diagnostic ultrasound. This initial screening method may assist surgeons as they consider graft selection for patients who may be at risk for developing or exacerbating preexisting patellofemoral joint or knee extensor mechanism conditions with BPTB autograft harvest.

An Australian survey of in-patient protocols for quadriceps exercises following anterior cruciate ligament reconstruction

Current practices regarding in-patient strengthening exercise prescription following anterior cruclate ligament (ACL) reconstruction are scarcely addressed in the literature and remain unreported for Australian hospitals. An observational, questionnaire-based study was used to Investigate in-patient quadriceps strengthening practices in Australian hospitals after ACL reconstruction. Questionnaires were returned by 248 hospitals (76% response rate) and of these 88 hospitals reported performing ACL reconstructions. These hospitals were surveyed to determine the types of quadriceps strengthening exercises prescribed during the in-patient period. Information was sought regarding routine management strengthening practices. A variety of quadriceps exercises such as static quadriceps contractions (SQC), straight leg raises (SLR) and inner range quadriceps (IRQ) were frequently prescribed, although no standard practice currently exists. Static quadriceps exercises were prescribed by 91% of hospitals surveyed, IRQ exercises were used by 30%, and 49% reported using SLR exercises. Current literature tends to support the performance of SQC and SLR exercises during the early postoperative period following ACL reconstruction. Conversely, current clinical practice is incongruent with regard to the scientific recommendations for IRQ performance.

Predicting physical therapy visits needed to achieve minimal functional goals after arthroscopic knee surgery

STUDY DESIGN

Retrospective, cross-sectional regression modeling.

OBJECTIVE

To predict physical therapy visits following arthroscopic knee surgery.

BACKGROUND

The number of physical therapy visits required to achieve a set of specific minimal-level goals (full knee extension, straight leg raise, normalized gait pattern, bicycle pedaling, and independent home exercises) that are related to decreased complication rates has not previously been modeled.

METHODS AND MEASURES

A multiple regression model to predict postoperative physical therapy visits was developed using subject demographics and 2 simple clinical measures, degree of straight leg raise lag and total range of motion. All data were collected from 148 patient charts. Model validity was examined by the predicted residual sum of squares technique and a second independent sample of 157 charts.

RESULTS

Diagnosis group, surgery group, and range of motion were the significant variables predicting visits in the final model (R2 = 0.384). Results of model validation analyses using predicted residual sum of squares technique (R2 = 0.346) and the second set of data (R2 = 0.282) were satisfactory. Analysis of residuals (difference of observed and predicted visits) showed prediction of the number of physical therapy visits within 3 visits for approximately 75% of the cases in both sets of data.

CONCLUSIONS

Using the model to predict physical therapy visits following arthroscopic knee surgery was more accurate than using diagnosis alone, except for lateral retinacular release. This study demonstrates how regression models could be used to explain variance in physical therapy visits for a given set of minimal functional goals.