DOI: 10.5301/hipint.5000131
Hip Int 2014; 24 ( 4): 387-393
ORIGINAL ARTICLE
Hip muscle strength recovery after hip arthroscopy in a series of patients with symptomatic femoroacetabular impingement Nicola C. Casartelli1,2, Nicola A. Maffiuletti1, Julia F. Item-Glatthorn1, Franco M. Impellizzeri1, Michael Leunig3 Neuromuscular Research Laboratory, Schulthess Clinic, Zurich - Switzerland INSERM U1093 - Cognition, Action and Sensory Plasticity, University of Burgundy, Dijon - France 3 Hip Service, Schulthess Clinic, Zurich - Switzerland 1 2
Purpose: The aim of the study was to prospectively evaluate hip muscle strength in a series of patients with symptomatic FAI after hip arthroscopy. Methods: Hip muscle strength of eight patients (age: 29 ± 10 years) was evaluated preoperatively and 2.5 years after hip arthroscopy, and was compared to eight matched controls. Maximal voluntary contraction (MVC) strength was measured for all hip muscle groups. At follow-up, we used the symptomspecific well-being outcome to assess the acceptability of the health state related to the hip. Results: Patients showed MVC strength increases for all hip muscles (9-59%, P.05] and height [FAI: 175 ± 6 cm vs. controls: 173 ± 9 cm, P>.05]. All patients had FAI diagnosed by the same senior surgeon based on patient history, physical examination, 388
radiographic and magnetic resonance imaging. Individual characteristics and diagnoses are itemised in Table I. All patients were participating in recreational sport activities before the onset of symptoms (2.8 ± 2.1 years before surgery). All patients underwent hip arthroscopy with an indication of hip pain and FAI diagnosis. Arthroscopies were performed with the patient in the supine position. The specific procedures, which were performed by the same senior surgeon, are itemised for each patient in Table I. After surgery, all patients underwent supervised physical therapy in our institution. Patients had on average 24 physical therapy sessions of 45 minutes. Control subjects were asymptomatic, had no history of hip pain, and were all participating in recreational sport activities. For both groups, subjects presenting any disorder to the lower extremities (excepting hip impingement in the FAI group) that would have negatively influenced muscle strength evaluation were not included in the study. The study was conducted according to the Helsinki Declaration and the protocol was approved by the local Ethics Committee. All the subjects signed a written informed consent before participating in the study.
Hip muscle strength Isometric maximal voluntary contraction (MVC) strength of the hip abductor, adductor, internal rotator, external rotator, flexor and extensor muscles was measured unilaterally (4). For patients, the symptomatic (patients with unilateral FAI) or the most symptomatic (patients with bilateral FAI) hip was tested, while controls had the respective hip evaluated, according to lower limb dominance (kicking limb). For practical reasons, hip abductors, adductors, internal rotators and external rotators were randomly tested first (restricted randomisation, random number table). Subsequently, hip flexors and extensors were assessed in a randomised order. The same testing order was used for patients in the two test sessions. All strength assessments were performed by the same experienced tester. Hip abductor, adductor, internal rotator and external rotator MVC strength was evaluated with hand-held dynamometry (Nicholas Manual Muscle Tester, Lafayette Inc., Lafayette, IN, USA) (4), while hip flexor and extensor MVC strength was assessed using an isokinetic dynamometer (Biodex System 2, Biodex Medical Systems, New York, USA). Muscle strength assessment positions have been described in detail in a
© 2014 Wichtig Publishing - ISSN 1120-7000
Casartelli et al
TABLE I - PATIENT CHARACTERISTICS, FAI-ASSOCIATED PATHOLOGY AND TREATMENT Patient number
Gender
Sport activity
FAI type
Structural and ligamentous abnormalities
Pathologies
Arthroscopic procedures
1
F
Dancing
Cam
Lack of anterior femoral offset, capsular laxity
Labral tear, cartilage defect (femur), capsular synovitis, adhesive capsulitis
Labral stabilisation, femoral neck osteoplasty, synovectomy
2
F
Martial arts
Combined (Pincer)
Acetabular retroversion, lack of anterior femoral offset, capsular laxity
Labral tear, capsular synovitis, adhesive capsulitis
Labral stabilisation, acetabular rim trimming, femoral neck osteoplasty, synovectomy
3
F
Snowboarding
Combined (Pincer)
Coxa profunda, lack of anterior femoral offset, capsular laxity
Labral tear, capsular synovitis, adhesive capsulitis
Labral stabilisation, femoral neck osteoplasty
4
F
Jogging
Combined (Cam)
Lack of anterior offset, acetabular retroversion, capsular laxity
Labral tear, capsular synovitis
Labral stabilisation, femoral neck osteoplasty
5
F
Fitness
Combined (Pincer)
Acetabular retroversion, lack of anterior femoral offset, capsular laxity
Labral tear, capsular synovitis, cartilage defect (acetabulum)
Labral stabilisation, acetabular rim trimming, femoral neck osteoplasty
6
M
Floorball
Combined (Cam)
Lack of anterior femoral offset, coxa profunda
Labral tear, cartilage defects (acetabulum)
Labral stabilisation, femoral neck osteoplasty, cartilage debridement, microfracturing
7
M
Soccer
Combined (Cam)
Lack of anterior femoral offset, coxa profunda
Labral tear, capsular synovitis, adhesive capsulitis
Labral stabilisation, femoral neck osteoplasty
8
M
Ice hockey
Pincer
Acetabular retroversion
Labral tear, cartilage defects (femur and acetabulum), capsular synovitis
Labral stabilisation
FAI = femoroacetabular impingement; F = female; M = male.
previous study (4). For each muscle group, subjects completed two submaximal familiarisation trials followed by 3-4 MVC trials (no more than 10% of difference between the two highest MVC was tolerated), during which they were asked to perform maximal efforts for 3-4 s. The rest interval between trials was 60 s. The main strength outcome was MVC torque normalised to body mass (14). For each muscle group, only the highest MVC value was retained. After each MVC trial, both patients and controls were asked to quantify hip pain by placing a vertical mark on a 100-mm horizontal line, known as the visual analogue scale (VAS) (15). The line ranges from 0 (no pain at all) to 100 (not endurable pain). For each muscle group, the mean pain score was retained.
Questionnaires The Hip Outcome Score (HOS) was used to evaluate hip pain and function during daily and sport activities (16). Two independent scores were obtained: one for activities of daily living (ADL: 19 items, 17 scored) and one for sport activities (sport: 9 items, 9 scored). The scores range from 0 to 100, where 100 represents the best possible score. The symptom-specific well-being outcome was used to assess the acceptability of the current health state related to the hip (17). It consists of one question (“If you had to spend the rest of your life with the symptoms you have now, how would you feel about it?”) and five response
© 2014 Wichtig Publishing - ISSN 1120-7000
389
Hip muscle strength after hip arthroscopy for FAI
options (“very satisfied”, “somewhat satisfied”, “neither satisfied nor dissatisfied”, “somewhat dissatisfied”, “very dissatisfied”). In addition, patients were asked about the changes that occurred as a result of hip arthroscopy in relation to hip pain and the ability to do sport by means of one question (“What changes in the following items have occurred as a result of the operation?”) and five response options (“much better”, “better”, “somewhat better”, “unchanged” and “worse”) (9).
Statistics Normal distribution of the data was assessed using Shapiro-Wilk tests. In case of normal distribution (muscle strength, HOS), data were presented as means ± SD and between- and within-group differences were investigated with paired t-tests. In case of non-normal distribution (hip pain during MVC trials), data were presented as medians and interquartile ranges and between- and within-group differences were investigated with Wilcoxon signed-rank tests. Percentage differences in MVC strength between patients and controls were calculated as (100 × (MVC strength of FAI – MVC strength of controls)/MVC strength of controls), while pre- to postoperative MVC strength changes were calculated as (100 × (postoperative MVC strength of FAI – preoperative MVC strength of FAI)/preoperative MVC strength of FAI). Statistical analyses were performed with SigmaPlot 11.0 software (Systat Software Inc., San Jose, CA, USA). The significance level was set at P
Hip Int 2014; 24 ( 4): 387-393
ORIGINAL ARTICLE
Hip muscle strength recovery after hip arthroscopy in a series of patients with symptomatic femoroacetabular impingement Nicola C. Casartelli1,2, Nicola A. Maffiuletti1, Julia F. Item-Glatthorn1, Franco M. Impellizzeri1, Michael Leunig3 Neuromuscular Research Laboratory, Schulthess Clinic, Zurich - Switzerland INSERM U1093 - Cognition, Action and Sensory Plasticity, University of Burgundy, Dijon - France 3 Hip Service, Schulthess Clinic, Zurich - Switzerland 1 2
Purpose: The aim of the study was to prospectively evaluate hip muscle strength in a series of patients with symptomatic FAI after hip arthroscopy. Methods: Hip muscle strength of eight patients (age: 29 ± 10 years) was evaluated preoperatively and 2.5 years after hip arthroscopy, and was compared to eight matched controls. Maximal voluntary contraction (MVC) strength was measured for all hip muscle groups. At follow-up, we used the symptomspecific well-being outcome to assess the acceptability of the health state related to the hip. Results: Patients showed MVC strength increases for all hip muscles (9-59%, P.05] and height [FAI: 175 ± 6 cm vs. controls: 173 ± 9 cm, P>.05]. All patients had FAI diagnosed by the same senior surgeon based on patient history, physical examination, 388
radiographic and magnetic resonance imaging. Individual characteristics and diagnoses are itemised in Table I. All patients were participating in recreational sport activities before the onset of symptoms (2.8 ± 2.1 years before surgery). All patients underwent hip arthroscopy with an indication of hip pain and FAI diagnosis. Arthroscopies were performed with the patient in the supine position. The specific procedures, which were performed by the same senior surgeon, are itemised for each patient in Table I. After surgery, all patients underwent supervised physical therapy in our institution. Patients had on average 24 physical therapy sessions of 45 minutes. Control subjects were asymptomatic, had no history of hip pain, and were all participating in recreational sport activities. For both groups, subjects presenting any disorder to the lower extremities (excepting hip impingement in the FAI group) that would have negatively influenced muscle strength evaluation were not included in the study. The study was conducted according to the Helsinki Declaration and the protocol was approved by the local Ethics Committee. All the subjects signed a written informed consent before participating in the study.
Hip muscle strength Isometric maximal voluntary contraction (MVC) strength of the hip abductor, adductor, internal rotator, external rotator, flexor and extensor muscles was measured unilaterally (4). For patients, the symptomatic (patients with unilateral FAI) or the most symptomatic (patients with bilateral FAI) hip was tested, while controls had the respective hip evaluated, according to lower limb dominance (kicking limb). For practical reasons, hip abductors, adductors, internal rotators and external rotators were randomly tested first (restricted randomisation, random number table). Subsequently, hip flexors and extensors were assessed in a randomised order. The same testing order was used for patients in the two test sessions. All strength assessments were performed by the same experienced tester. Hip abductor, adductor, internal rotator and external rotator MVC strength was evaluated with hand-held dynamometry (Nicholas Manual Muscle Tester, Lafayette Inc., Lafayette, IN, USA) (4), while hip flexor and extensor MVC strength was assessed using an isokinetic dynamometer (Biodex System 2, Biodex Medical Systems, New York, USA). Muscle strength assessment positions have been described in detail in a
© 2014 Wichtig Publishing - ISSN 1120-7000
Casartelli et al
TABLE I - PATIENT CHARACTERISTICS, FAI-ASSOCIATED PATHOLOGY AND TREATMENT Patient number
Gender
Sport activity
FAI type
Structural and ligamentous abnormalities
Pathologies
Arthroscopic procedures
1
F
Dancing
Cam
Lack of anterior femoral offset, capsular laxity
Labral tear, cartilage defect (femur), capsular synovitis, adhesive capsulitis
Labral stabilisation, femoral neck osteoplasty, synovectomy
2
F
Martial arts
Combined (Pincer)
Acetabular retroversion, lack of anterior femoral offset, capsular laxity
Labral tear, capsular synovitis, adhesive capsulitis
Labral stabilisation, acetabular rim trimming, femoral neck osteoplasty, synovectomy
3
F
Snowboarding
Combined (Pincer)
Coxa profunda, lack of anterior femoral offset, capsular laxity
Labral tear, capsular synovitis, adhesive capsulitis
Labral stabilisation, femoral neck osteoplasty
4
F
Jogging
Combined (Cam)
Lack of anterior offset, acetabular retroversion, capsular laxity
Labral tear, capsular synovitis
Labral stabilisation, femoral neck osteoplasty
5
F
Fitness
Combined (Pincer)
Acetabular retroversion, lack of anterior femoral offset, capsular laxity
Labral tear, capsular synovitis, cartilage defect (acetabulum)
Labral stabilisation, acetabular rim trimming, femoral neck osteoplasty
6
M
Floorball
Combined (Cam)
Lack of anterior femoral offset, coxa profunda
Labral tear, cartilage defects (acetabulum)
Labral stabilisation, femoral neck osteoplasty, cartilage debridement, microfracturing
7
M
Soccer
Combined (Cam)
Lack of anterior femoral offset, coxa profunda
Labral tear, capsular synovitis, adhesive capsulitis
Labral stabilisation, femoral neck osteoplasty
8
M
Ice hockey
Pincer
Acetabular retroversion
Labral tear, cartilage defects (femur and acetabulum), capsular synovitis
Labral stabilisation
FAI = femoroacetabular impingement; F = female; M = male.
previous study (4). For each muscle group, subjects completed two submaximal familiarisation trials followed by 3-4 MVC trials (no more than 10% of difference between the two highest MVC was tolerated), during which they were asked to perform maximal efforts for 3-4 s. The rest interval between trials was 60 s. The main strength outcome was MVC torque normalised to body mass (14). For each muscle group, only the highest MVC value was retained. After each MVC trial, both patients and controls were asked to quantify hip pain by placing a vertical mark on a 100-mm horizontal line, known as the visual analogue scale (VAS) (15). The line ranges from 0 (no pain at all) to 100 (not endurable pain). For each muscle group, the mean pain score was retained.
Questionnaires The Hip Outcome Score (HOS) was used to evaluate hip pain and function during daily and sport activities (16). Two independent scores were obtained: one for activities of daily living (ADL: 19 items, 17 scored) and one for sport activities (sport: 9 items, 9 scored). The scores range from 0 to 100, where 100 represents the best possible score. The symptom-specific well-being outcome was used to assess the acceptability of the current health state related to the hip (17). It consists of one question (“If you had to spend the rest of your life with the symptoms you have now, how would you feel about it?”) and five response
© 2014 Wichtig Publishing - ISSN 1120-7000
389
Hip muscle strength after hip arthroscopy for FAI
options (“very satisfied”, “somewhat satisfied”, “neither satisfied nor dissatisfied”, “somewhat dissatisfied”, “very dissatisfied”). In addition, patients were asked about the changes that occurred as a result of hip arthroscopy in relation to hip pain and the ability to do sport by means of one question (“What changes in the following items have occurred as a result of the operation?”) and five response options (“much better”, “better”, “somewhat better”, “unchanged” and “worse”) (9).
Statistics Normal distribution of the data was assessed using Shapiro-Wilk tests. In case of normal distribution (muscle strength, HOS), data were presented as means ± SD and between- and within-group differences were investigated with paired t-tests. In case of non-normal distribution (hip pain during MVC trials), data were presented as medians and interquartile ranges and between- and within-group differences were investigated with Wilcoxon signed-rank tests. Percentage differences in MVC strength between patients and controls were calculated as (100 × (MVC strength of FAI – MVC strength of controls)/MVC strength of controls), while pre- to postoperative MVC strength changes were calculated as (100 × (postoperative MVC strength of FAI – preoperative MVC strength of FAI)/preoperative MVC strength of FAI). Statistical analyses were performed with SigmaPlot 11.0 software (Systat Software Inc., San Jose, CA, USA). The significance level was set at P
