The Etiology and Arthroscopic Surgical Management of Cam Lesions

A Sport-specific Analysis of the Epidemiology of Hip Injuries in National Collegiate Athletic Association Athletes From 2009 to 2014

PURPOSE

To describe the injury rates, mechanisms, time loss, and rates of surgery for hip/groin injuries in National Collegiate Athletic Association (NCAA) athletes across 25 collegiate sports during the 2009/10 to 2013/14 academic years.

METHODS

Data from the 2009/10 to 2013/14 academic years were obtained from the NCAA Injury Surveillance Program (ISP). Rates of hip/groin injuries, mechanism of injury, time lost from competition, and surgical treatment were calculated. Differences between sex-comparable sports were quantified using rate ratios and injury proportion ratios. A sport-specific biomechanical classification system, which included cutting, impingement, overhead/asymmetric, endurance, and flexibility sports, was applied for subgroup analysis.

RESULTS

In total, 1,984 hip injuries were reported in 25 NCAA sports, including 9 male and female sports, 3 male-only sports, and 4 female-only sports between the years 2009/10 and 2013/14, resulting in an overall hip injury rate of 53.1/100,000 athletic exposures (AEs). In sex-comparable sports, (basketball, cross-country, lacrosse, ice hockey, indoor track, outdoor track, soccer, swimming, and tennis), men were more commonly affected than women (59.53 vs 42.27 per 100,000 AEs respectively; rate ratio, 1.41; 95% confidence interval, 1.28-1.55). Subgroup analysis demonstrated that the highest rate of hip injuries per 100,000 AEs occurred in impingement sports (96.9). Endurance sports had the highest proportion of injured athletes with time lost >14 days (9.5%). For impingement-type sports, the most common mechanism of injury was no apparent contact (48.2%). The rate of athletes undergoing surgery per 100,000 AEs was highest in impingement-type sports (2.0).

CONCLUSIONS

We have identified that impingement-type sports are most frequently associated with hip injuries. Additionally, this study demonstrates that hip injuries sustained in athletes who played impingement-type sports had a significantly higher rate of surgical intervention than other sport classifications.

LEVEL OF EVIDENCE

Level III, prognostic study.

Prevalence of femoroacetabular impingement and effect of training frequency on aetiology in paediatric football players

PURPOSE:

The aim of this study was to determine the prevalence of asymptomatic radiographic findings of femoroacetabular impingement (FAI) in paediatric football players in different age groups and to investigate aetiological factors.

METHODS:

Paediatric male athletes between 10 and 17 years of age from 8 soccer teams were recruited. In addition to an annual control check-up, anteroposterior pelvis and frog-leg radiographs as well as the curriculum vitae of the athletes, their injuries, and real-time complaints were recorded. The alpha angle, lateral centre-edge angle, Tönnis angle, and collodiaphyseal angle were measured and morphological abnormalities were noted.

RESULTS:

There were 214 male football players with a mean age of 13.4 ± 3.2 years included in the study. In the morphological analysis of hips, there was FAI in 30% of the athletes. In the analysis of FAI prevalence in 3 subgroups based on age (Group 1: 10-12 years [ n = 25], Group 2: 13-15 years [ n = 104], Group 3: 16-17 years [ n = 85]), there was 0% FAI in Group 1, 19.1% in Group 2 and 60% in Group 3. In the analysis of aetiological factors, there was no significant difference between the right and left hips of players regarding alpha angles and FAI prevalence. However, the prevalence of FAI was higher in players who had been playing football for 3 years or more and who had been training for 12.5 hours/week or more.

CONCLUSION:

Training for 12.5 hours or more per week in paediatric football players doubled the risk development of FAI morphology.

In Search of the Spherical Femoroplasty: Cam Overresection Leads to Inferior Functional Scores Before and After Revision Hip Arthroscopic Surgery

BACKGROUND

Femoroplasty performed for the treatment of cam-type femoroacetabular impingement (FAI) has become a common procedure. Underresection may result in residual FAI. Conversely, overresection may disrupt the labral seal, which is responsible for chondroprotective fluid dynamics of the hip. Hypothesis/Purpose: It was hypothesized that cam overresection negatively affects hip function. The purpose was to examine the effect of the accuracy of previous femoroplasty on hips presenting for revision hip arthroscopic surgery.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected for patients presenting for revision hip arthroscopic surgery between June 2010 and August 2014. On the basis of measurements on Dunn view radiographs, cases were divided into 3 groups: overresection (OR group) in which overresection measured over 5% of the diameter of the femoral head, underresection (UR group) in which there was a residual cam lesion (alpha angle >60°), and neutral resection (neutral group). Data collection included the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Hip Outcome Score-Sports-Specific Subscale, and visual analog scale at presentation and at a minimum 2-year follow-up after revision hip arthroscopic surgery and rates of conversion to total hip arthroplasty (THA).

RESULTS

One hundred thirty hips (120 patients) were included. Twenty hips (15.4%) were classified as the OR group, 16 (12.3%) as the UR group, and 94 (72.3%) as the neutral group. The mean follow-up was 39.6 ± 15.9 months. The mHHS and NAHS values at presentation were lower in the OR group compared with the UR group (50.2 ± 15.5 vs 64.7 ± 19.4 [ P = .033] and 48.5 ± 18.6 vs 63.0 ± 19.1 [ P = .044], respectively). The mHHS value at a minimum 2-year follow-up after revision was lower for the OR group (66.7 ± 19.8) than for the UR group (81.0 ± 14.5) ( P = .031). Conversion to THA was more common in the OR group than in the UR group (30% vs 0%, respectively; P = .024). Fifty percent of cases in the OR group, 69.9% in the neutral group, and 75% in the UR group met the minimal clinically important difference for the mHHS (Δ). The latest mHHS value reached the patient acceptable symptomatic state (PASS) in 35% of the cases in the OR group, 53.2% in the neutral group, and 75% in the UR group. Hips in the OR group had a significantly lower chance of reaching the PASS than the UR group (odds ratio, 0.1795 [95% CI, 0.0418-0.7711]; P = .0209).

CONCLUSION

Cam overresection of more than 5% of the diameter of the femoral head on the Dunn view predicts inferior clinical outcomes compared with cam underresection in this population. Furthermore, overresection predicts inferior outcomes after revision hip arthroscopic surgery and higher rates of conversion to THA.

Anterior Inferior Iliac Spine Morphology and Outcomes of Hip Arthroscopy in Soccer Athletes: A Comparison to Nonkicking Athletes

PURPOSE

To describe the anterior inferior iliac spine (AIIS) morphology and clinical outcomes following arthroscopic surgical decompression in a group of high-level soccer athletes presenting with symptomatic hip impingement when compared with a control group of nonkicking athletes.

METHODS

From 2009 to 2012, we retrospectively reviewed our prospective hip registry for soccer athletes who underwent arthroscopic treatment for femoroacetabular impingement (FAI) with 2-year follow-up, comparing with a control group of nonkicking athletes. Demographics were collected and radiographic studies (plain radiograph and computed tomographic scan) reviewed for several parameters, including AIIS morphology. Patient-reported outcome scores, including modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL) and Sport-Specific Subscale (HOS-SSS), and International Hip Outcome Tool-33 (iHOT-33), were administered preoperatively, at 6 months, and at 1, 2, and 3 years postoperatively.

RESULTS

Twenty-six soccer players (34 hips) and 87 nonkicking athletes (115) hips were identified. Demographics, including age (19.2 ± 4.1 vs 20.1 ± 3.8 years) and gender distribution (53.8% vs 51.7% male), were similar between the soccer and nonkicking athletes (P = .288, .849). Eighty-four percent of soccer players demonstrated some abnormality of the AIIS extending to (type II, 52%) or below the anterior acetabular rim (type III, 32%), compared with 52% nonkicking athletes (P < .001). At a mean follow-up of 35 months (range, 24-57 months) there was significant improvement in all outcome scores in both groups from pre- to postoperation (P < .001). There was no evidence of differences in outcome scores between groups (mHSS: 89 ± 14.6 vs 88.2 ± 14.4, P = .804; HOS-ADL: 94.1 ± 9.1 vs 92.2 ± 11.1, P = .431; HOS-SSS: 86 ± 17.1 vs 81.3 ± 24.3, P = .362) with the exception of iHOT-33 (81.7 ± 19 vs 70.3 ± 23.6, P = .027).

CONCLUSIONS

High-level soccer players have a significantly higher rate of subspine impingement compared with nonkicking athletes. There should be a high index of suspicion when treating soccer players for FAI, where appropriate recognition and treatment of subspine impingement can yield excellent clinical results.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.