Thigh and Calf Girth Following Knee Injury and Surgery

Transcription

1 Thigh and Calf Girth Following Knee Injury and Surgery Capt Michael Ross, MSEd, PT' Teddy W. Worrell, EdD, PT, SCS, ATC, FACSM F ollowing knee injury or surgery, muscle atrophy is often assessed as part of a clinical evaluation (5,6, 12). Several authors have recommended evaluating muscle atrophy through girth measures in order to document one aspect of asymmetry between involved and noninvolved extremities (4,13,14). Recently, thigh girth measures were shown to be significantly correlated with measures of thigh muscle crosssectional area taken by computed tomography in patients with chronic anterior cruciate ligament insufficiency, even though the girth measures underestimated the decrease in muscle cross-sectional area seen in these patients (12). Soderberg et al (17) reported that thigh and calf girth measurements for the involved extremity were less than the noninvolved extremity in subjects following anterior cruciate ligament reconstruction. Soderberg et a1 (l7), however, did not report presurgical girth measurements; therefore, they were unable to determine if the difference in girth measurements existed prior to surgery. To our knowledge, no study has assessed thigh and calf girth measurements following knee injury and sub sequent surgery. In our opinion, girth measurements may have important implications relative to the rehabilitation of the lower extremity following knee injury and surgery. Therefore, the purpose of this study was to compare Rfrth measurements of the thigh and calf between Girth measures are commonly used to assess muscle atrophy or joint effusion. Little is known, however, regarding girth measurement changes following knee injury and subsequent surgery. Therefore, the purpose of this study was to compare the thigh and calf girth measurements of involved and noninvolved extremities prior to and following knee surgery for subjects with acute and chronic knee injuries. Of the 40 subjects that were studied, 22 subjects were placed in the acute group (less than 6 months from time of injury to presurgery measurement) and 18 subjects were placed in the chronic group (greater than 6 months from time of injury to presurgery measurement). Thigh and calf girth measurements were taken prior to surgery and then prior to the initiation of outpatient rehabilitation following surgery. For the acute and chronic groups, a threeway analysis of variance (ANOVA) with repeated measures on the extremity, muscle, and time factors was used to analyze the data. For each group, the three-way ANOVA revealed a significant two-way interaction between the extremity and time factors. Post hoc analysis revealed significant differences between involved and noninvolved extremities at both the pre- and post-surgery time periods for the acute and chronic groups. While thigh and calf girth measurement differences existed between the involved and noninvolved extremities prior to and after surgery, the bulk of the girth measurement differences existed prior to surgery for both groups. Based upon the results of this study, the assessment and rehabilitation of the thigh and calf following knee injury and surgery are recommended. Key Words: knee, surgery, thigh girth, calf girth ' Assistant Chief, Department of Physical Therapy, 96th Medical Group, Eglin Air Force Base, FL. Captain Ross completed this study in partial fulfillment of the requirements for an advanced master of health science degree in physical therapy, University of Indianapolis, Indianapolis, IN. Address for correspondence: 96th MSGS/SGCPY, 307 Boatner Road, Suite 114, Eglin Air Force Base, FL Associate Professor and Director of Research, Krannert School of Physical Therapy, University of Indianapolis, Indianapolis, IN Note: The opinions expressed herein are those of the authors and do not necessarily reflect the opinions of the Department of Defense, the United States Air Force, or other federal agencies. involved and noninvolved extremities prior to and following knee surgery for acute (less than 6 months from time of injury to time of presurgical measurement) and chronic (greater than 6 months from time of injury to time of presurgical measurement) groups. For both the acute and chronic groups, we hypothesized that: 1) thigh and calf girth measurements of the involved extremity are diminished compared with the noninvolved extremity prior to and following knee surgery, and 2) a larger percentage of the girth measurement differences between involved and noninvolved extremities occurs prior to surgery. METHODS Subjects Forty subjects participated in this study. Inclusion requirements were unilateral knee arthroscopic surgery and thigh and calf girth measurements taken less than 1 week prior to knee surgery and then prior to the JOSPT Volume 27 Number 1 *January 1998

2 Acute Croup Chronic Group noninvolved extremities. A single investigator took all measurements. Age (yean) Days presurgery Days postsurgery Weeks injured TABLE 1. Description of subjects for acute (N = 22: 18 males, four females) and chronic groups (N = 18: 13 males, five femdles). initiation of outpatient physical therapy following surgery. Of the 40 sub jects, 22 subjects were less than 6 months from the time of initial injury to the time of presurgical measurement and 18 subjects were greater than 6 months from the time of initial injury to the time of presurgical measurement (Table 1). A descrip tion of the surgical procedures is presented in Table 2. Prior to participation, informed consent was obtained from each subject. Girth Measurement Procedure For the thigh girth measurements, subjects were placed in a supine position with their knees extended and lower extremity musculature relaxed. Girth measurements were taken at 10 and 20 cm proximal to the superior patellar pole after this distance was measured and marked on the skin of the anterior thigh with an ink pen. Girth measurement of the calf took place with subjects positioned prone, with their knees extended and lower extremity musculature relaxed. Prior to formally measuring calf girth, it was necessary to determine the region of the calf that was greatest in circumference on the noninvolved extremity, as this point would serve as the landmark for each of the calf measurements. After identification of the calf region that was largest in girth on the noninvolved extremity, a mark was placed at this point on the skin of the lateral aspect of the calf with an ink pen. The distance from this point to the distal aspect of the fibular head was measured. Then, on the involved extremity, this distance from the fibular head was measured and marked. The distance from the fibular head was documented during the presurgery measurement and used as a landmark during the postsurgery measurement. All measurements were taken with a nonelastic tape measure. Two girth measurements were taken at each of the three sites on the involved and noninvolved extremity prior to and following surgery. Care was taken to remove the slack from the tape measure without significantly compressing the limb musculature. Except for determination of the region that was greatest in calf girth, the order of measuring was randomized with respect to involved and Surgical Procedure Acute Group Chronic Group (M (M Menisectomy 7 7 Anterior cruciate ligament reconstruction 2 5 Debridement of arthrofibrosis 2 3 Osteophytdoose body resection 4 0 Chondroplasty 2 1 Lateral release 2 1 Diagnostic arthroscope 2 0 Plica resection 1 1 TABLE 2. Description of surgical procedures. 10 Reliability Study Prior to the descriptive study, 10 normal subjects without history of lower extremity pathology were measured bilaterally as described above to determine intrasession and intersession reliability of the girth measurement techniques. For intersession reliability, subjects were measured 7 days apart. Girth measurements were randomized relative to extremities, except for the determination of the maximum calf girth landmark, which was initially done on the subject's dominant extremity. Statistical Analysis For the reliability study, intraclass correlation coefficients (ICC 2.1) (16) and standard errors of measurement (SEM) (2) were used to assess reliability of the girth measurement techniques. A three-way analysis of variance (ANOVA) with repeated measures on the extremity, muscle, and time factors was used to analyze the girth measures for the acute and chronic groups. The potential main effect of muscle and muscle by time interaction was not considered valid because of the inherent girth differences of the thigh and calf. The potential main effect for time also was not considered valid since the extremity and muscle factors were collapsed prior to and following surgery. Therefore, the interaction of interest was extremity by time. The alpha level was set at p Reliability Study Intrasession ICCs were.99 for each of the three girth measurement sites and SEMs ranged from.26 to.38 cm. Intersession measurement ICCs and SEMs ranged from.98 to Volume 27 Number 1 Januav 1998 JOSPT

3 lntrajession Thigh 20 cm Thigh 10 cm Calf Source df SS MS F P Muscle 2 Extremity 1 Error 17 Intersession Thigh 20 cm Thigh 10 cm Calf Thigh 20 cm = 20 cm proximal to superior patellar pole. Thigh 10 cm = 10 cm proximal to superior patellar pole. Calf = Region of largest girth ( cm distal from fibular head). SEM = Standard e m of measurement. TABLE 3. Reliabilify data for girth measurements..99 and.26 to.54 cm, respectively (Table 3). Descriptive Study For the acute and chronic groups, there was a significant main effect for the muscle and extremity factors, as well as a significant interaction between the extremity and time factors (Tables 4 and 5, Figures 1 and 2). Post hoc testing of the simple Time 1 Error 17 Muscle x Extremity 2 Muscle X Time 2 Extremity X Time 1 Error 17 Extremity x Muscle X Time 2 TABLE 5. Summary of three-way analysis of variance for chronic group. main effects revealed significant differences between the involved and noninvolved extremities for the acute and chronic groups at both the preand post-surgical time periods (Table 6) (9). For the acute group, a significant main effect occurred for time as well as a significant interaction between the muscle and extremity factors, neither of which were considered valid (Table 4). Table 6 includes the collapsed means and standard Source df SS MS F P Muscle Error Extremity Error Time Error Muscle X Extremity oOol Error Muscle X Time Error Extremity X Time oOol Error Extremity X Muscle X Time Error TABLE 4. Summary of three-way analysis of variance for acute group. deviations of the three girth measurement sites for pre- and post-surgery measurements for involved and noninvolved extremities for acute and chronic groups, respectively. Table 7 includes the means and standard deviations of pre- and post-surgery measurements for involved and noninvolved extremities at the three girth measurement sites for all subjects. DISCUSSION Excellent reliability was demonstrated for intrasession and intersession testing (ICC >.go), and small measurement error existed for both sessions (<.54 cm) (7). We, therefore, concluded that our measurement procedures were acceptable for the descriptive study. Our hypotheses that the thigh and calf girth measurements of the involved extremity would be diminished compared with the noninvolved extremity prior to and following knee surgery and that the majority of the girth measurement differences would exist prior to surgery for both acute and chronic groups were supported by the data. These hypotheses were based on the inhibiting effect that knee injury and surgery may have on JOSPT Volume 27 Number 1 January 1998

4 quadriceps (5,6), hip (lo), and ankle muscle function (8). Authors have reported that following injury, an altered gait (21) and reflex muscle inhibition often result (19). An altered gait, which may elicit decreased weight-bearing forces and altered muscle function, combined with the effects of reflex inhibition, may result in disuse atrophy. The results of this study reveal that while a significant difference in girth measurements between the involved and noninvolved extremities was present for both groups, the bulk of the girth measurement differences existed prior to surgery (Figures 1 and 2). At the time of the presurgery measurement, 77% (17 out of 22) of the subjects in the acute group and 78% (14 out of 18) of the subjects in the chronic group reported pain in their involved knee. We speculate that the knee pain reported by this large percentage of subjects may have contributed to the aforementioned mechanisms and the girth measurement differences seen prior to surgery. We placed subjects into acute and chronic groups to control the length of time from injury to the time of the presurgery girth measurements, as this may have been a confounding variable. Six months was arbitrarily chosen as the time line between the two groups. We conclude that both groups responded similarly from pre- to post-surgical measures, ie., the involved extremity decreased in girth (acute group =.5 cm, chronic group =.29 cm) and the noninvolved extremity increased in girth (acute group =.2 cm, chronic group =.13 cm) following knee surgery. We theorized that the small, additional decrease in girth measurement seen in the involved extremity following surgery may be related to the pain and effusion associated with knee surgery causing further inhibition and disuse atrophy of the thigh and calf musculature. The girth differences between the involved and noninvolved extremities for both groups prior to and following surgery, as noted in Table 6, were greater than the measurement error that was determined in the reliability study (Table 3). Therefore, we conclude that our findings represent actual thigh and calf girth measurement differences between the involved and noninvolved extremities for both groups. The results of our study suggest that the majority of the lower extremity girth measurement differences existed prior to surgery. By examining the collapsed data from the three girth measurement sites, it is noted that the acute group's noninvolved extremity was 2.06 cm (4.15%) and 2.76 cm (5.54%) larger pre- and postsurgically, respectively (Table 6). The FIGURE 1. Pre- and post-surgical girth measurements of involved and noninvolved extremities for acute group. pre = Presurgery; post = Postsurgery; inv = Involved; noninv = Noninvolved. Results of our study suggest that the majority of the lower extremity girth measurement differences existed prior to surgery chronic group's noninvolved extremity was 1.25 cm (2.59%) and 1.67 cm (3.46%) larger pre- and post-surgically, respectively (Table 6). Despite the relatively small absolute differences between involved and noninvolved extremities for each of the groups, the differences were in the 2-6% range. Our results are in agreement with those of Soderberg et al (1 7), who reported individual thigh and calf girth measurement differences between involved and noninvolved extremities of 3-7% in nine subjects following anterior cruciate ligament reconstruction. Again, we feel that the girth measurement differences seen in our study between the involved and noninvolved extremities are relevant because they exceed the intersession measurement error. Despite the girth measurement differences noted between the involved and noninvolved extremities for both the acute and chronic groups, we are unable to discern if the presurgery differences between the involved and noninvolved extremities were due to atrophy of the involved extremity or hypertrophy of the noninvolved extremity. Furthermore, we were unable to determine at what time following injury or surgery the changes in lower extremity girth measurements took place. However, the results of studies that have examined the effects of immobilizing animal hind limbs suggest that the greatest muscle atrophy occurs during the initial days of immobiliira- Volume 27 Number 1.January 1998 JOSPT

5 FIGURE 2. Pre- andpost-surgicalgirth measurements of involvedand noninvolved extremities for chronicgroup. pre = Presurgery; post = Postsurgery; inv = Involved; noninv = Noninvolved. tion and only small changes in muscle mass occur beyond 7-10 days (l,3). We did not attempt to correlate girth measurement differences with functional capabilities. Therefore, we do not know at what point girth measurement differences interfere with functional capacity. Several authors, however, have shown relatively small changes in muscle size to be associated with significant changes in strength (5.1 1,12). Lorentzon et a1 (12) found a 5.1 % decrease in quadriceps cross-sectional area and a % decrease in knee extensor peak torque for the involved extremity in 19 subjects with untreated chronic anterior cruciate ligament injuries. Elmqvist et al (5) found a 6.3% decrease in quadriceps crosssectional area and an approximately 15-25% decrease in quadriceps peak torque for the involved extremity in 11 subjects with chronic tears of the anterior cruciate ligament. LeBlanc et al (1 1 ) reported a 12 and 26% decrease in ankle plantar flexor crosssectional area and strength, respectively, in nine subjects that underwent a 5-week bedrest protocol. In each of these studies, a small loss of muscle cross-sectional area resulted in a larger loss of muscular strength. This suggests that other factors in addition to muscle size, such as neurologic inhibition or loss of neural drive, may be responsible for the decreased strength seen following injury or immobilization (8). In our study, thigh and calf girth measurements were compared between involved and noninvolved extremities prior to and following knee surgery. We did not take preinjury (an) SD Diff (on) Oh Diff SD Diff (an) % Diff Acute group Noninvolved * * 5.54 Involved Chronic group Noninvolved ' ' 3.46 Involved * Significant diiirrencrs rp , noted between extremities Diti = Noninvolved - involved. % Diff = (Noninvolved - involved)/noninvolved X 100. TABLE 6. Collapsed pre- and post-surgical thigh and calf girth measurement data for involved and noninvolved extremities. measurements or determine whether girth measurement differences existed between dominant and nondominant extremities. Therefore, we do not know if girth measurement differences existed prior to injury or the effect of extremity dominance on thigh and calf girth. However, Whitney et al (20) determined that girth measures of the thigh and calf are equal between extremities in subjects without history of lower extremity pathology. We did not correct for the effect of subcutaneous fat on girth measurements in this study nor did Lorentzon et al (12), who concluded that thigh girth measurements were significantly correlated (r =.69, p < 0.01) with measures of thigh muscle cross-sectional area taken by computed tomography in patients with chronic anterior cruciate ligament insufficiency. Despite this finding by Lorentzon et al (12), girth measurements should be viewed with caution because of inherent inabilities to differentiate between changes localized to contractile and noncontractile tissues. Evidence exists, however, that suggests differential muscle atrophy takes place in the thigh and calf regions (1 l,l5). Sargeant et al (15) reported that in the thigh following injury or immobilization, the greatest loss in muscular bulk may be confined to the quadriceps compared with the other muscles. Similar differential muscle atrophy has been shown to take place in the calf following immobilization (1 1). LeBlanc et al (1 1) reported significant ankle plantar flexor atrophy in subjects following 5 weeks of bed rest, with no significant change in muscle area noted for the ankle dorsiflexors. Traditionally, it has been believed that the vastus medialis muscle atrophies at a greater rate when compared with the other components of the quadriceps (19). Our research, as well as that of Soderberg et al (1 7), demonstrates girth measurement differences between the involved and noninvolved extremities at both the JOSPT Volume 27 Number 1 January 1998

6 Site x (cm) Resugcy Data SD Diff(cm) % Diff Thigh 20 cm Noninvolved Involved Thigh 10 cm Noninvolved Involved calf Noninvolved Involved Thigh 20 cm = 20 cm proximal to superior patellar pole. Thigh 10 cm = 10 cm proximal to superior patellar pole. Cali = Region of largest girth. Diff = - involved. % Diff = [Noninvolved- invol~/noninvolved X 100. Postsurgery Data - - (cm) SD Diff (cm) % Diff TABLE 7. Pre- and post-surgical descriptive data for involved and noninvolved extremities for all subjects. distal and proximal thigh. While girth measurement differences between the involved and noninvolved extremities taken 10 cm proximal to the superior patellar pole pre- and post-surgery were 2.01 cm (4.03%) and 2.61 cm (5.22%), respectively, girth measurement differences taken 20 cm proximal to the superior patellar pole pre- and post-surgery were 1.84 cm (3.14%) and 2.52 cm (4.29%), respectively (Table 7). While both thigh girth measurement sites exhibited girth measurement differences between the involved and noninvolved extremities prior to and following knee surgery, the majority of the girth measurement differences for both thigh girth measurement sites existed prior to surgery. We believe this suggests that a similar pat- Studies that have examined the effects of immobilizing animal hind limbs suggest that the greatest muscle atrophy occurs during the initial days of immobilization. tern of girth measurement differences existed throughout the thigh between the involved and noninvolved extremities prior to and following surgery. By means of ultrasound scanning techniques, it has been further suggested that the quadriceps components are affected in a similar manner following knee injury (22). Additionally, following knee joint injections with saline and measurements of reflex inhibition via Hoffman reflexes, Spencer et al (18) concluded that although the vastus medialis muscle was affected first compared with the rectus femoris and vastus lateralis muscles, reflex inhibition significantly affected all components of the quadriceps. While quadriceps activation has been shown to be severely limited following knee surgery (lg), further studies should be done to investigate the effect of knee surgery on calf muscle activation (ie., electromyographic recruitment patterns), although recent research has shown significant strength loss of the ankle plantar and dorsiflexors 3 weeks following anterior cruciate ligament reconstruction (8). Clinical Implications 11,12), a thorough assessment of thigh and calf girth and strength following knee injury and surgery is recommended. Moreover, assessment of hip muscle strength should be included (10). Thus, the entire lower extremity kinetic chain should be assessed. Since knee pain and effusion may have an inhibitory effect on lower extremity muscle function (10, 18), the application of appropriate anti-inflammatory measures (ie., ice, elevation, compression bandaging) is recommended. After steps have been taken to control knee pain and effusion, appropriate rehabilitation exercises should be prescribed to facilitate lower extremity motor control. Additionally, since the majority of thigh and calf girth differences between the involved and noninvolved extremities existed prior to surgery in this study, emphasis on presurgical evaluation and intervention is recommended. CONCLUSION The results of this study indicate that significant thigh and calf girth measurement differences were evident between the involved and noninvolved extremities prior to and following knee surgery for both the acute and chronic groups, with the majority of the girth measurement differences existing prior to surgery. This suggests that appropriate rehabilitative measures should be taken to minimize thigh and calf girth measurement differences between involved and noninvolved extremities, especially prior to surgery. JOSPT REFERENCES I. Appell HI: Morphology of immobilized skeletal muscle and the effects of a oreand postimmobilization training program: Int ] Sports Med 7:6-12, Baumeartner TA: Norm-referenced measlrements: Reliability. In: Safrit M, Woods T (eds): Measurement Concepts in Physical Education and Exercise Science,' pp Champaign, IL: Hu- Based upon the results of our study and the reported relationship of small changes in muscle size with significant decreases in strength (5, man Kinetics Publishers, 1989 Volume 27 Number 1 January 1998 JOSPT

7 Booth FW: Time course of muscular atrophy during immobilization of hindlimbs in rats. ] Appl Physiol 43: , Courson R: Role of evaluation in the rehabilitation program. In: Andrews JR, Harrelson GL (eds): Physical Rehabilitation of the Injured Athlete, p 51. Philadelphia, PA: W. 6. Saunders Company, Elmqvist L, Lorentzon R, Johansson C, Fugl-Meyer AR: Does a torn anterior cruciate ligament lead to change in the central nervous system drive of the knee extensors? Eur J Appl Physiol58: , Elmqvist L, Lorentzon R, Johansson C, Langstrom M, Fagerlund M, Fugl-Meyer AR: Knee extensor muscle function before and after reconstruction of anterior cruciate ligament tear. Scand J Rehabil Med21: , Fleiss JL: The Design and Analysis of Clinical Experiments, pp New York, NY: John Wiley & Sons, Herlant M, Delahaye H, Voisin P, Bibre P, Adele MF: The effect of anterior cruciate ligament surgery on the ankle plantar flexors. Isokin Exerc Sci 2(3): , Hinkle DE, Wiersma W, Jurs SG: Ap- plied Statistics for the Behavioral Sciences (2nd Ed), pp ?. Boston, MA: Houghton Mifflin Company, Jaramillo J, Worrell TW, lngersoll CD: Hip isometric strength following knee surgery. J Orthop Sports Phys Ther 20(3): , LeBlanc A, Gogia P, Schneider V, Krebs J, Schonfeld E, Evans H: Calf muscle area and strength changes after five weeks of horizontal bed rest. Am J Sports Med 16(6): , Lorentzon R, Elmqvist LG, Sjostrom M, Fagerlund M, Fugl-Meyer AR: Thigh musculature in relation to chronic anterior cruciate ligament tear Muscle size, morphology, and mechanical output before reconstruction. Am ] Sports Med 1 7(3): , Magee Dl: Orthopaedic Physical Assessment (2nd Ed), p 423. Philadelphia, PA: W.B. Saunders Company, 19%' 14. Nitz A], Bellew JW, Hazle CR: Evaluation of the musculoskeletal disorders. In: Malone TR, McPoil T, Nitz A] (eds), Orthopaedic and Sports Physical Therapy (3rd Ed), p 175. St Louis, MO: Mosby-Year Book, Inc., Sargeant A], Davies CTM, Edwards HT, Maunder C, Young A: Functional and structural changes after disuse of hu- man muscles. Clin Sci , Shrout PE, Fleiss TL: lntraclass correlation: Uses in assessing rater reliability. Psycho1 Bull 86: , Soderberg GL, Ballantyne BT, Kestel L: Reliability of lower extremity girth measurements after anterior cruciate ligament reconstruction. Physiother Res Int 1 (l):7-16, Spencer JD, Hayes KC, Alexander I]: Knee effusion and quadriceps reflex inhibition in man. Arch Phys Med Rehabil 65: , Stokes M, Young A: The contribution of reflex inhibition to arthrogenous muscle wasting. Clin Sci 67:7-14, Whitney SL, Mattocks L, lrrgang 11, Gentile PA, Pezzullo D, Kamkar A: Reliability of lower extremity girth measurements and right- and left-side differences. J Sport Rehabil4(2): , Whittle M: Gait Analysis: An Introduction, pp Oxford, England: Buttenvorth-Heinemann, Young A, Hughes I, Round JM, Edwards RH: The effect of knee injury on the number of muscle fibers in the human quadriceps fernoris. Clin Sci 62: , 1982 JOSPT Volume 27 Number 1 January 1998