Search

Purpose The purpose of the present study was to evaluate the outcome of arthroscopic treatment for femoroacetabular impingement (FAI) syndrome 5 years post-surgery using patient-reported outcome scores (PROMs) validated for a young and active population with hip complaints. Methods Patients were prospectively included in the study. A total of 184 patients [males = 110 (59.8%), females = 74 (40.2%)], with mean age 38.0, underwent arthroscopic treatment for FAI syndrome and were analysed. Preoperatively and at the 5-year follow-up, patients completed a set of self-administered web-based PROMs consisting of the International Hip Outcome Tool (iHOT-12), the Copenhagen Hip and Groin Outcome Score (HAGOS), the Hip Sports Activity Scale (HSAS), the EuroQoL-5 Dimension Questionnaire (EQ-5D), the EQ-Visual Analogue Scale (VAS) and the VAS for overall hip function and overall satisfaction. The Wilcoxon signed rank test was used to compare preoperative PROM values with those obtained at the 5-year follow-up. Results A comparison of preoperative PROM scores and those obtained at the 5-year follow-up revealed statistically significant improvements for all outcome scores (p

Purpose: To translate and culturally adapt the Hip Sports Activity Scale (HSAS) to Swedish and validate the Swedish version in patients with femoroacetabular impingement (FAI) syndrome. Materials and Method: The original German version was translated to Swedish. To determine reliability, validity, and floor and ceiling effects, a questionnaire set consisting of the Swedish version of the HSAS, the Copenhagen Hip and Groin Outcome Score (HAGOS), the short version of the international hip outcome tool, and the Tegner Activity Scale was completed pre‐operatively by 30 patients planned for arthroscopic hip surgery for FAI syndrome. To determine responsiveness, pre‐operative and one‐year follow‐up HSAS data from 30 patients treated with arthroscopic hip surgery for FAI syndrome were collected. Results: For test‐retest reliability, the interclass correlation was 0.930. The HSAS correlated to the Tegner score (r = 0.794, P < 0.01), as well as to the HAGOS subscale of “physical activity” (r = 0.436, P < 0.05). Cohen's effect size and the standardized response mean were 0.25 and 0.28, respectively. Ceiling and floor effects were between 7% and 10%. Conclusion: The Swedish version of the HSAS is a reliable and valid measurement to determine sports activity levels in patients with FAI syndrome.

Background There is conflicting evidence regarding the association between cam morphological changes and hip pain, and it remains unclear who with cam morphology will develop hip pain and who will not. This study aimed to investigate the correlation between cam morphology, hip pain, and activity level at a 5-year follow-up in young Alpine and Mogul skiers. Method All students (n = 76) at Åre Ski National Sports High School were invited and accepted participation in this prospective study at baseline. Magnetic resonance imaging (MRI) of both hips was conducted to evaluate the presence of cam morphology (α-angle ≥ 55°) and its size alongside the reporting of hip pain, type, and frequency of training by the Back and hip questionnaire, at baseline. After 5 years, the skiers were invited to complete a shortened version of the same questionnaire. Results A total of 60 skiers (80%) completed the follow-up questionnaire, of which 53 had concomitant MRI data. Cam morphology was present in 25 skiers (47.2%, 39 hips). Hip pain at baseline and at follow-up was reported in 17 (28.3%) and 22 (36.7%) skiers, respectively. No correlations were found between the activity level, the frequency, and the size of cam morphology and hip pain, except for the right hip α-angle at 1 o’clock and hip pain in skiers with cam morphology at baseline (rs = 0.49; P = 0.03) and at follow-up (rs = 0.47; P = 0.04). A total of 73.3% skiers had retired, of which 48% reported this was due to injuries. Conclusion Hip pain was not shown to be correlated, or had a low correlation, with activity level and the presence and size of cam morphology in young skiers on a 5-year follow-up. Based on these results, cam morphology or activity level did not affect hip pain to develop during 5 years of follow-up in young skiers. Furthermore, this study highlights that almost 75% of young elite skiers had retired from their elite career with almost 50% reporting that this was due to injuries sustained from skiing.

Additional file 1.

Purpose To investigate the prevalence of cam morphology in (1) a group of young elite Mogul and Alpine skiers compared with non-athletes and (2) between the sexes. Method The hip joints of 87 subjects [n = 61 young elite skiers (29 females and 32 males) and n = 26 non-athletes (17 females and 9 males)] were examined using MRI, for measurements of the presence of cam morphology (α-angle ≥ 55). Results The skiers had a significantly higher prevalence of cam morphology compared with the non-athletes (49% vs 19%, p = 0.009). A significant difference (p

Background:Femoroacetabular impingement (FAI) syndrome is a cause of pain and reduced range of motion in the hip joint. Given the limited number of randomized controlled trials, prospective cohort studies constitute the dominant part of the available prospective evidence evaluating relevant clinical outcomes after arthroscopic hip surgery for FAI.Purpose:To assess the methodological quality of prospective cohort studies evaluating arthroscopic surgery for FAI and to determine whether there has been an improvement in methodological quality over time.Study Design:Systematic review; Level of evidence, 4.Methods:A systematic literature search was performed in PubMed, Embase (OvidSP), and the Cochrane Library. Included studies were clinical prospective cohort studies of primary arthroscopic surgery for cam and/or pincer morphology FAI. Methodological quality was assessed with the Methodological Index for Non-randomized Studies (MINORS). The mean MINORS score for studies published during the first 5 years of the period was compared with those published during the last 5 years to evaluate methodological improvement over time. The methodological quality of randomized controlled trials was also assessed with the Coleman Methodology Score.Results:The search yielded 53 studies. There were 34 noncomparative studies, 15 nonrandomized comparative studies, and 4 randomized controlled trials. The included studies were published between 2008 and 2017. The mean ± SD MINORS score for noncomparative and comparative studies was 10.4 ± 1.4 of 16 possible and 18.7 ± 2.0 of 24 possible, respectively. The mean Coleman Methodology Score for randomized controlled trials was 79.0 ± 7.0 of 100 possible.Conclusion:The methodological quality of prospective cohort studies evaluating arthroscopic surgery for FAI is moderate for comparative and noncomparative studies. Common areas for improvement include unbiased assessment of study endpoints and prospective sample-size calculations. Despite an increase in the number of published studies, an improvement in methodological quality over time was not observed.

Osteoarthritis (OA) of the hip is a common cause of hip pain. The arthroscopic management of patients with femoro-acetabular impingement (FAI) has been reported to yield good outcomes. The purpose of this study was to report on outcome following the arthroscopic treatment of patients with FAI in the presence of mild to moderate OA. Seventy-five patients undergoing arthroscopic surgery for FAI, all with preoperative radiological signs of mild to moderate OA were prospectively included in this study. A 2-year follow-up, using web-based patient-reported outcome measures, including the International Hip Outcome Tool (iHOT-12), Copenhagen Hip and Groin Outcome (HAGOS), EQ-5D, Hip Sports Activity Scale (HSAS) for physical activity level and a visual analogue scale (VAS) for overall hip function, was performed, complemented by a radiographic evaluation. At follow-up (mean 26 months, SD 5), five patients (7%) had undergone total hip arthroplasty, leaving 70 patients for the analysis. Preoperative scores compared with those obtained at the 2-year follow-up revealed significant improvements (P

Anna Swärd Aminoff,1 Cecilia Agnvall,2,3 Carl Todd,1 Páll Jónasson,4 Mikael Sansone,1 Olof Thoreson,1 Leif Swärd,1 Jon Karlsson,1 Adad Baranto1 1Department of Orthopaedics, Institute of Clinical Sciences at Sahlgrenska Academy, University of Gothenburg, and Sahlgrenska University Hospital, Gothenburg, Sweden; 2Sports Medicine Åre, Åre, Sweden; 3Åre Ski Academy, Åre, Sweden; 4Orkuhúsið Orthopedic Clinic, Reykjavik, Iceland Background: Current knowledge of the effect of changes in posture and the way cam morphology of the hip joint may affect hip range of motion (ROM) is limited. Purpose: To determine the effect of changes in pelvic tilt (PT) on hip ROM and with/without the presence of cam. Study design: This was a cross-sectional study. Materials and methods: The hip ROM of 87 subjects (n=61 young elite skiers, n=26 nonathletes) was examined using a goniometer, in three different seated postures (flexed, neutral, and extended). The hips of the subjects were further subgrouped into cam and no-cam morphology, based on the magnetic resonance imaging findings in the hips. Results: There was a significant correlation between the hip ROM and the seated posture in both extended and flexed postures compared with the neutral posture. There was a significant decrease in internal hip rotation when the subjects sat with an extended posture with maximum anterior PT (p

Purpose To investigate how range of motion of the hips and the lumbar spine are affected by continued elite, alpine skiing in young subjects, with and without a magnetic resonance imaging verified cam morphology, in a 2-year follow-up study. The hypothesis is that skiers with cam morphology will show a decrease in hip joint range of motion as compared with skiers without cam, after a 2-year follow-up. Method Thirty adolescent elite alpine skiers were examined at the baseline (mean age 17.3 ± 0.7 years) and after 2 years. All skiers were examined for the presence of cam morphology (α-angle > 55°) using magnetic resonance imaging at the baseline. Clinical examinations of range of motion in standing lumbar flexion and extension, supine hip flexion, internal rotation, FABER test and sitting internal rotation and external rotation were performed both at the baseline and after 2 years. Results Skiers with and without cam morphology showed a significant decrease from baseline to follow-up in both hips for supine internal rotation (right: mean − 13.3° and − 10.9° [P

Background The biomechanical mechanisms of failure of FSUs have been studied but the correlation of repetitive flexion and extension loadings to the initial phase of fatigue in young FSUs are still not known. The purpose of the study was to examine the fatigue results of low magnitude repetitive flexion and extension loading on porcine lumbar Functional Spinal Units (FSUs) with Magnetic Resonance Imaging (MRI) and histology. Methods Eight FSUs were subject to repetitive pivot flexion and eight to extension loading by a protocol of 20 000 cycles at 1 Hz with a load of 700 N. All loaded FSUs (N = 16) were examined with MRI and histology post loading. Three FSUs were examined with MRI as controls. Further three FSUs were non loaded histology controls. Results Fifteen (94%) of the loaded FSUs have decreased MRI signal in the growth zone of the superior vertebra and 12 (75%) in the inferior vertebrae. Fourteen (88%) FSUs have increased signal in the superior vertebral body. Fourteen (88%) FSUs have a reduced signal in all or any endplate. The histology morphometry displayed that the unstained parts of the epiphyseal growth zone were larger among the loaded FSUs (mean 29% vs 4%) and that the chondrocytes in the endplate and growth zones had abnormal structure and deformed extracellular matrix. Conclusion Repetitive loading of young porcine FSUs in both extension and flexion causes concurrent MRI and histological changes in the growth zones and endplates, which could be a first sign of fatigue and an explanation for the disc, apophyseal and growth zone injuries seen among adolescent athletes.

There are several reports on the association between pubalgia and intra-articular hip disorders. The purpose of this study was to evaluate the long-term outcome in athletes who underwent tenotomy due to long-standing groin pain. A secondary purpose was evaluating the frequency of femoro-acetabular impingement (FAI) and its impact on the long-term outcome.Thirty-two high-level male athletes treated with adductor tenotomy, rectus abdominis tenotomy or both were included. At a median follow-up time of 6 years after the tenotomy, the subjects underwent standardised clinical examination, plain radiographs, completed web-based health-related patient-reported outcomes, including iHOT12, HAGOS (six subscales), EQ-5D (two subscales), HSAS for physical activity level and a VAS for overall hip function. Furthermore, patient satisfaction and return to sports were documented.Twenty-four of the 32 (75 %) athletes were satisfied with the outcome of the tenotomy, and 22 of the athletes (69 %) were able to return to their pre-injury sport. Before the long-term follow-up, two of these satisfied athletes had undergone repeat surgery (one hip arthroscopy due to FAI and one repeat tenotomy). Of the 24 satisfied athletes, eight (33 %) had a positive hip impingement test at the follow-up. Of the remaining eight athletes not satisfied with the outcome, only one returned to their pre-injury sport and three had undergone hip arthroscopy prior to follow-up. Five had positive hip impingement tests which was significantly more frequently than in the satisfied group (p = 0.008). The group with a positive hip impingement test reported significantly more pain and symptoms, more hip problems during sports and physical activity, as well as lower hip-related quality of life according to the HAGOS scores (p0.05), at follow-up.Tenotomy for pubalgia yielded a satisfactory long-term outcome, with three of four athletes being able to return to their pre-injury sport. The athletes that did not return to their pre-injury sport had higher frequency of positive hip impingement test and inferior functional outcome compared with the athletes that did return to their pre-injury sport. It is therefore recommended that the hip should be carefully evaluated for hip impingement before tenotomy is considered as treatment for athletes with pubalgia.

There is a lack of standardised outcome measures in Swedish for active, young and middle-aged patients with hip and groin disability. The purpose of this study was to adapt the Danish version of the Copenhagen Hip and Groin Outcome Score (HAGOS) patient-reported outcome instrument for use in Swedish patients and evaluate the adaptation according to the Consensus-Based Standards for the Selection of Health Status Measurement Instruments checklist.Cross-cultural adaptation was performed in several steps, including translation, back-translation, expert review and pretesting. The final version was evaluated for reliability, validity and responsiveness. Five hundred and two patients (337 men and 167 women, mean age 37, range 15-75) were included in the study.Cronbach's alpha for the six HAGOS-S subscales ranged from 0.77 to 0.89. Significant correlations were obtained with the international Hip Outcome Tool average score (r s = 0.37-0.68; p0.01) and a standardised instrument, the EuroQol, EQ-5D total score (r s = 0.40-0.60, p = 0.01), for use as a measurement of health outcome. Test-retest reliability (intraclass correlation coefficient) ranged from 0.81 to 0.87 for the six HAGOS-S subscales. The smallest detectable change ranged from 7.8 to 16.1 at individual level and 1.6-3.2 at group level. Factor analysis revealed that the six HAGOS-S subscales had one strong factor per subscale. Effect sizes were generally medium or large.The Swedish version of the HAGOS is a valid, reliable and responsive instrument that can be used both for research and in the clinical setting at individual and group level.

The hip is a highly stable joint. Non-traumatic dislocation of the hip is extremely uncommon. In this article, we report two cases of non-traumatic hip dislocations following hip arthroscopy. In both cases, capsulotomy and ileopsoas tenotomy had been performed. These cases raise questions about the importance of the natural stabilisers of the hip. Level of evidence V.

Bone development occurs through either intramembranous ossification (mesenchymal or connective tissue) or enchondral ossification, where bone is formed from hyaline cartilage. The flat bones of the skull and the mandible, maxilla and clavicles are formed by intramembranous ossification. The long bones and spine and most of the other bones of the axial skeleton are formed by enchondral ossification. In this chapter, the growth and development of the hip, particularly the proximal femur, is reviewed as well as the pathways for the development of adaptive bony changes leading to FAI.

Introduction: The spino-pelvic complex in humans helps to maintain an upright posture, by balancing the spinal sagittal alignment with the hip joints and pelvic girdle. The extent of how the hip joint may influence the spino-pelvic alignment is not fully understood. Hip joint cam femoro-acetabular impingement is a common source of hip and groin disability in young athletes and has been linked to abnormal joint morphology from repetitive loading of the proximal femoral head abutting against the acetabulum. The aim of this study was to compare the radiological parameters of spino-pelvic sagittal alignment and spinal types according to Roussouly’s classification in relation to hip joint cam femoro-acetabular impingement. Methods: The sample group (n=102), mean age (17.7 ± 1.4) years, consisted of elite skiers (n=75) and nonathletes (n=27). Hip joints were examined for increased morphological cam deformity, (alpha angle greater than 55o) with Magnetic Resonance Imaging and standing lateral plain radiographs were taken for measurements of the spinopelvic sagittal alignment. Results: A significant difference was shown in a mixed population (skiers and non-athletes) for an increased Pelvic Tilt angle (13°, SD 10.2) in the presence of morphological hip joint cam deformity compared with participants without cam deformity (8.5°, SD 7.1, P=0.036). Type II Roussouly spines occurred more frequently in skiers in the presence of increased cam (67%) compared with no cam (33%), however, this was not significant (P=0.19). Secondary findings highlighted significant differences shown for the prevalence of cam in a mixed-population for gender; males 60% (n=26) shown to have significantly more cam deformity compared with females 22% (n=10, P=0.001). Similar for height, with taller participants being shown to have significantly more cam deformity >177cm (SD 7.6) compared with no cam deformity

Femoroacetabular impingement (FAI) is a common cause of hip pain and dysfunction. The purpose of this study was to report outcome 2 years after the arthroscopic treatment of FAI using validated outcome measurements. Two hundred and eighty-nine patients (males = 190, females = 99) with a mean age of 37 years underwent arthroscopic surgery for FAI. Patients were included consecutively in a hip arthroscopy registry. The cohort was evaluated using online web-based validated health-related patient-reported outcomes measurements, including the iHOT-12, HAGOS, EQ-5D, HSAS for physical activity level, VAS for overall hip function and overall satisfaction. The mean follow-up time was 25.4 months. Pre-operative scores compared with those obtained at follow-up revealed statistically and clinically significant improvements (P

Background: Femoroacetabular impingement (FAI) is a common cause of hip pain and dysfunction among athletes. Although arthroscopic surgery is an established treatment option for FAI, there are few studies reporting detailed outcomes using validated outcome measurements specifically designed for young and active athletes. Purpose: To report outcomes 1 year after arthroscopic treatment of FAI in top-level athletes using validated outcome measurements adapted for a young and active population. Study Design: Case series; Level of evidence, 4. Methods: A total of 85 top-level athletes (68 males, 17 females) with a mean (±SD) age of 25 ± 5 years underwent arthroscopic surgery for FAI. All athletes who reported Hip Sports Activity Scale (HSAS) levels 7 or 8 (range, 0-8) prior to symptom onset were included. The cohort was prospectively evaluated using online web-based validated health-related patient-reported outcomes measures (HR-PROMs), including the short version of the International Hip Outcome Tool (iHOT-12), the Copenhagen Hip and Groin Outcome Score (HAGOS; 6 subscales), the EuroQOL 5 dimensions questionnaire (EQ-5D; 2 subscales), the Hip Sports Activity Scale (HSAS) for physical activity level, and a visual analog scale (VAS) for overall hip function. Furthermore, patients reported their overall satisfaction with treatment. Results: The mean follow-up time was 12.3 ± 0.6 months. Preoperative scores compared with those obtained at the 12-month follow-up revealed statistically and clinically significant improvements ( P < .0001) for all measured outcomes: iHOT-12 (42 vs 73), VAS for global hip function (52 vs 77), HSAS (4.3 vs 5.7), EQ-5D index (0.60 vs 0.83), EQ-VAS (68 vs 82), and HAGOS subscales (60 vs 83, 50 vs 73, 66 vs 86, 39 vs 75, 27 vs 70, and 34 vs 67). At the 12-month follow-up, 79 athletes (93%) reported that they were satisfied with the outcome of surgery. At follow-up, 62 athletes (73%) had returned to competitive sports (HSAS levels 5-8) and 44 (52%) to their previous HSAS level of activity (HSAS level 7 or 8). Twenty-three athletes (27%) did not return to competitive sports (HSAS level ≤4). Significantly lower levels of return to sports were seen with longer symptom duration ( P < .05). Conclusion: Twelve months after surgery, arthroscopic treatment for FAI in top-level athletes resulted in statistically and clinically significant improvements at the group level in all outcome parameters for pain, symptoms, function, physical activity level, quality of life, and general health. One year after surgery, approximately 3 of 4 top-level athletes had returned to sports.

Joint-related pain conditions from the spine and extremities are common among top athletes. The frequency of back pain has, however, been studied in more detail, and the frequency of low-back pain in top athletes in different high-load sports has been reported to be as high as 85%. Sport-related pain from different joints in the extremities is, however, infrequently reported on in the literature. Seventy-five male athletes, i.e. divers, weight-lifters, wrestlers, orienteers and ice-hockey players and 12 non-athletes (control group) were included in the study. A specific self-assessed pain-oriented questionnaire related to the cervical, thoracic and lumbar spine, as well as the various joints, i.e. shoulders, elbows, wrists, hips, knees and ankles, was filled out by the athletes and the non-athletes. The overall frequency of pain reported by the athletes during the last week/last year was as follows; cervical spine 35/55%; thoracic spine 22/33%; lumbar spine 50/68%; shoulder 10/21%; elbow 7/7%; wrist 7/8%; hip 15/23%; knee 22/44%; and ankle 11/25%. The corresponding values for non-athletes were cervical spine 9/36%; thoracic spine 17/33%; lumbar spine 36/50%; shoulder 0/9%; elbow 9/0%; wrist 0/0%; hip 9/16%; knee 10/9%; and ankle 0/0%. A higher percentage of athletes reported pain in almost all joint regions, but there were no statistically significant differences (n.s.), with the exception of the knees (P = 0.05). Over the last year, athletes reporting the highest pain frequency in the lumbar spine were ice-hockey players and, in the cervical spine, wrestlers and ice-hockey players. The highest levels of knee pain were found among wrestlers and ice-hockey players, whereas the highest levels for wrist pain were found among divers, hip pain among weight-lifters, orienteers and divers and ankle pain among orienteers. For the thoracic spine, shoulder and elbow regions, only minor differences were found. There was no statistically significant difference in prevalence of pain in the neck, spine and joints between top athletes in different sports or between athletes and non-athletes. However, pain in one spinal region was correlated to reported pain in other regions of the spine. Moreover, pain in the spine was also correlated to pain in the shoulders, hips and knees. Prognostic case–control study, Level III.

Background The high loads on adolescent athletes’ musculoskeletal system are known to cause morphological and degenerative changes in bone, intervertebral discs and joints. It has been suggested that the cam deformity of the proximal femoral head originates from a subclinical slipped capital femoral epiphysis (SCFE) as a result of non-physiological loading. The perichondrial fibrocartilaginous complex (PFC) and the epiphyseal tubercle are believed to stabilise the proximal femoral epiphysis, but their role is still unclear. The aim of the present study was to develop an experimental, biomechanical model to evaluate the strength of the porcine proximal femoral epiphysis in different loading directions and, furthermore, to investigate the stabilising role of the PFC and the epiphyseal tubercle. Methods A descriptive laboratory study. An in-vitro model was developed and nine young (5 months) porcine proximal femoral epiphyses were loaded to failure; three in the anterior-posterior direction, three in the lateral-medial direction and three in the vertical direction. The injured proximal femoral epiphyses were then examined both macroscopically and histologically. Results Anterior and lateral loading of the proximal femoral epiphysis resulted in failure of the epiphyseal plate, while vertical loading resulted in a fracture epiphyseolysis. The epiphysis was weakest when exposed to a lateral load and strongest when exposed to a vertical load. Despite histological epiphyseolysis, the PFC was intact in 15 of 27 (56%) slices. In histological examinations, the epiphyseal tubercle appears to halt the slide of the epiphysis. Conclusions We have developed an experimental, biomechanical model to measure the strength of the proximal femoral epiphyseal plate in different loading directions. The strength of the proximal femur was weakest through the epiphyseal plate. The epiphysis was weakest when exposed to a lateral load and strongest when exposed to a vertical load. The epiphyseal tubercle and the PFC stabilise the epiphysis when the epiphyseal plate is damaged. The findings in the present study indicate that overloading the hips in growing individuals can disrupt the epiphyseal plate. These findings may have implications when it comes to understanding the pathogenesis of cam deformity of the hip.

Background The repetitive load to which the adolescent athlete’s body is exposed during training and competition affects bone growth. In previous studies, abnormalities of the spine and extremities of adolescent athletes have been described on radiographs and this also applies to the hip. The cam deformity of the hip is an extension of the physeal plate and develops during the adolescent athlete’s growth. Studies of the porcine spine have shown that the vertebral endplates, apophyseal rings and intervertebral discs are susceptible to both static and repetitive loads. The proximal physeal plate of the porcine femur is susceptible to static loads, but no studies have been performed on its susceptibility to repetitive loads. The purpose of this study was to investigate the susceptibility of the proximal porcine femur to repetitive loads. Methods Descriptive laboratory study. Seven proximal femurs from four young (5 months) pigs were loaded repetitively (50,000 cycles) using a previously developed model. Three were loaded vertically, three antero-superiorly and one was used as a control. All femurs were examined macroscopically, histologically and with MRI after loading. Results No macroscopic injuries were detected on any of the femurs after loading. Fluid redistribution was seen in all femurs on MRI compared with the unloaded control. Injuries were seen in all loaded femurs on microscopic examination of histological samples. Injuries, perpendicularly to the physeal plate and fractures adjacent to the plate, were seen in the vertically loaded specimens. In the antero-superiorly loaded specimen, the injury in the growth plate was parallel to the plate. Conclusion Repeated loading of the young porcine hip leads to histological injuries in and adjacent to the physeal plate. These injuries are likely to cause growth disturbances in the proximal femur. We propose that such injuries may be induced in adolescent athletes and offer a plausible explanation for the development of the cam deformity.