Borderline acetabular dysplasia remains a controversial topic in hip preservation, with poor current comparative literature to guide accurate diagnosis and treatment decision making. Borderline ...dysplasia represents a "transitional acetabular coverage" pattern between more classic acetabular dysplasia and normal coverage. Traditionally, borderline dysplasia has been defined by a lateral center-edge angle between 20° and 25°, whereas more recently, some authors have used 18° to 25°. Treatment decisions between isolated hip arthroscopy (addressing labral tears, femoroacetabular impingement morphology, and capsular laxity) and periacetabular osteotomy (improving joint stability, often combined with arthroscopy) remain challenging because the fundamental mechanical diagnosis (instability vs femoroacetabular impingement) can be difficult to determine clinically. Obtaining an accurate diagnosis to direct surgical treatment relies on comprehensive assessment of additional bony anatomy features (including femoral version) and patient characteristics (including sex, soft-tissue laxity, and range of motion). Future research efforts in borderline dysplasia should better characterize the role of disease- and patient-specific factors that will inform accurate diagnoses, leading to the development of optimal treatment strategies in distinct patient subgroups through comparison of treatment outcomes.
In the last 20 years, femoroacetabular impingement (FAI) has transitioned from a disputed disease to a well-established cause of hip pain and osteoarthritis (OA). Cam-type FAI, specifically, is ...supported by several studies as a risk factor for osteoarthritis. Elevated α-angle is also a mild-to-moderate risk factor for OA in patients with FAI. Other risk factors include age, sex, body mass index, activity level, range of motion, 3D acetabular and femoral morphology, and femoral version. To further complicate the picture, when we look at the contralateral hip (where many of these factors are held constant), only about 25% of patients appear to report symptoms over a 5-year period after their presentation with ipsilateral FAI. In the setting of an FAI bony morphology, some individuals end up with early symptoms and cartilage damage at a young age, while others go their whole life without hip pain. We still have a long way to go to understand the multitude of factors that drive the “perfect storm” that leads to symptomatic FAI and eventual OA in certain patients.
Meniscal repair offers the potential to avoid the long-term articular cartilage deterioration that has been shown to result after meniscectomy. Failure of the meniscal repair can occur several years ...postoperatively. Limited evidence on the long-term outcomes of meniscal repair exists.
We performed a systematic review of studies reporting the outcomes of meniscal repair at a minimum of five years postoperatively. Pooling of data and meta-analysis with a random-effects model were performed to evaluate the results.
Thirteen studies met the inclusion criteria. The pooled rate of meniscal repair failure (reoperation or clinical failure) was 23.1% (131 of 566). The pooled rate of failure varied from 20.2% to 24.3% depending on the status of the anterior cruciate ligament (ACL), the meniscus repaired, and the technique utilized. The rate of failure was similar for the medial and the lateral meniscus as well as for patients with an intact and a reconstructed ACL.
A systematic review of the outcomes of meniscal repair at greater than five years postoperatively demonstrated very similar rates of meniscal failure (22.3% to 24.3%) for all techniques investigated. The outcomes of meniscal repair at greater than five years postoperatively have not yet been reported for modern all-inside repair devices.
Background:
Femoroacetabular impingement (FAI) is recognized as a common cause of hip pain and intra-articular disorders in athletes. Studies have suggested a link between participation in athletics ...during adolescence and the development of cam-type deformities of the proximal femoral head-neck junction.
Purpose:
To investigate the association of sporting activity participation during adolescence and the development of cam deformity.
Study Design:
Systematic review.
Methods:
The PubMed, EMBASE, and Cochrane databases were searched to identify potential studies. Abstracts and manuscripts (when applicable) were independently reviewed by 2 reviewers. Nine studies met the inclusion criteria, including 8 studies that compared the prevalence of cam deformity in athletes with that in controls and 3 studies that compared the prevalence of cam deformity before and after physeal closure (2 with both). A meta-analysis was performed with pooling of data and random-effects modeling to compare rates of cam deformity between athletes and controls.
Results:
High-level male athletes are 1.9 to 8.0 times more likely to develop a cam deformity than are male controls. The pooled prevalence rate (by hip) of cam deformity in male athletes was 41%, compared with 17% for male controls. The pooled mean alpha angle among male athletes was 61°, compared with 51° for male controls.
Conclusion:
Males participating in specific high-level impact sports (hockey, basketball, and possibly soccer) are at an increased risk of physeal abnormalities of the anterosuperior head-neck junction that result in a cam deformity at skeletal maturity.
Background
Hip dysplasia represents a spectrum of complex deformities on both sides of the joint. Although many studies have described the acetabular side of the deformity, to our knowledge, little ...is known about the three-dimensional (3-D) head and neck offset differences of the femora of dysplastic hips. A thorough knowledge of proximal femoral anatomy is important to prevent potential impingement and improve results after acetabular reorientation.
Questions/purposes
(1) Are there common proximal femoral characteristics in patients with symptomatic hip dysplasia undergoing periacetabular osteotomy (PAO)? (2) Where is the location of maximal femoral head and neck offset deformity in hip dysplasia? (3) Do certain subgroups of dysplastic hips more commonly have cam-type femoral morphology? (4) Is there a relationship between hip ROM as well as impingement testing and 3-D head and neck offset deformity?
Methods
Using our hip preservation database, 153 hips (148 patients) underwent PAO from October 2013 to July 2015. We identified 103 hips in 100 patients with acetabular dysplasia (lateral center-edge angle LCEA < 20°) and who had a Tönnis grade of 0 or 1. Eighty-six patients (86%) underwent preoperative low-dose pelvic CT scans at our institution as part of the preoperative planning for PAO. It is currently our standard to obtain preoperative low-dose pelvic CT scans (0.75–1.25 mSv, equivalent to three to five AP pelvis radiographs) on all patients before they undergo PAO unless a prior CT scan is performed at an outside institution. Hips with a history of a neuromuscular disorder, prior trauma, prior surgery, radiographic evidence of joint degeneration, ischemic necrosis, or Perthes-like deformities were excluded. Fifty hips in 50 patients met inclusion criteria and had CT scans available for review. Hips were analyzed with Dyonics Plan software and characterized with regard to version, neck-shaft angle, femoral head diameter, head and neck offset, femoral neck length, femoral offset, head center height, trochanteric height, and alpha angle. The maximum head and neck offset deformity was assessed using an entire clockface and an alpha angle ≥ 55° defined coexisting cam morphology. Subgroups included severity of lateral dysplasia: mild (LCEA 15°–20°) and moderate/severe (LCEA < 15°). Femoral version subgroups were defined as normal (5°–20°), decreased (≤ 5°), or increased (> 20°). The senior author (JCC) performed all physical examination testing.
Results
The mean LCEA was 14° (±4°), whereas the mean femoral anteversion was 19° (±12°). Eight hips (16%) demonstrated relative femoral retroversion (≤ 5°), whereas 26 (52%) showed excessive femoral anteversion (> 20°). Four hips (8%) had ≥ 35° of femoral anteversion. The mean neck-shaft angle was 136° (±5°). The mean maximum alpha location was 2:00 o’clock (±45 minutes) and the mean maximum alpha angle was 52° (±6°). Minimum head-neck offset ratio was located at 1:30 with a mean of 0.14 (±0.03). An anterior head-neck offset ratio of ≤ 0.17 or an alpha angle ≥ 55° was found in 43 (86%) of hips. Twenty-one dysplastic hips (42%) had an alpha angle ≥ 55°. Mildly dysplastic hips had decreased femoral head and neck offset (9 ± 1) and head and neck offset ratio (0.20 ± 0.03) at 12 o’clock compared with moderate/severe dysplastic hips (10 ± 1 and 0.22 ± 0.03, respectively; p = 0.04 and p = 0.01). With the numbers available, we found that hips with excessive femoral anteversion (> 20°) had no difference in the alpha angle at 3 o’clock (42 ± 7) compared with hips with relative femoral retroversion (≤ 5°; 48 ± 4; p = 0.06). No other differences in femoral morphology were found between hips with mild or moderate/severe dysplasia or in the femoral version subgroups with the numbers available. Anterior impingement test was positive in 76% of hips with an alpha angle ≥ 55° and 83% of the hips with an alpha angle ≤ 55°. No correlation was found between proximal femoral morphology and preoperative ROM.
Conclusions
In this subset of dysplastic hips, cam deformity of the femoral head and neck was present in 42% of hips with maximal head-neck deformity at 2 o’clock, and 82% had reduced head-neck offset at the 1:30 point. We conclude that cam-type deformities and decreased head-neck offset in developmental dysplasia of the hip are common. Patients should be closely assessed for need of a head and neck osteochondroplasty, especially after acetabular correction. Future prospective studies should evaluate the influence of proximal femoral anatomy on surgical results of PAO for dysplastic hips.
Level of Evidence
Level IV, prognostic study.
Purpose
The acetabular labrum is theorized to be important to normal hip function by providing stability to distraction forces through the suction effect of the hip fluid seal. The purpose of this ...study was to determine the relative contributions of the hip capsule and labrum to the distractive stability of the hip, and to characterize hip stability to distraction forces in six labral conditions: intact labrum, labral tear, labral repair (looped vs. through sutures), partial resection, labral reconstruction with iliotibial band, and complete resection.
Methods
Eight cadaveric hips with a mean age of 47.8 years (SD 4.3, range 41–51 years) were included. For each condition, the hip seal was broken by distracting the hip at a rate of 0.33 mm/s while the required force, energy, and negative intra-articular pressure were measured. For comparisons between labral conditions, measurements were normalized to the intact labral state (percent of intact).
Results
The relative contribution of the labrum to distractive stability was greatest at 1 and 2 mm of displacement, where it was significantly greater than the role of the capsule and accounted for 77 % (SD 27 %,
p
= 0.006) and 70 % (SD 7 %,
p
= 0.009) of total distractive stability, respectively. The relative contribution of the capsule to distractive stability increased with progressive displacement, providing 41 % (SD 49 %) and 52 % (SD 53 %) of distractive stability at 3 and 5 mm of distraction, respectively. The maximal distraction force required to break the hip seal in the intact labral state (capsule removed) varied from 124 to 150 N. Labral tear, partial resection, and complete resection resulted in average maximal distraction forces of 76 % (SD 34 %), 29 % (SD 26 %), and 27 % (SD 22 %), respectively, compared to the intact state. Through type labral repairs resulted in significantly greater improvements (from the labral tear state) in maximal negative pressure generated, compared to looped type repairs (median increase; +32 vs. −9 %,
p
= 0.029). Labral reconstruction resulted in a mean maximal distraction force of 66 % (SD 35 %), with a significant improvement of 37 % compared to partial labral resection (
p
< 0.001).
Conclusion
The acetabular labrum was the primary hip stabilizer to distraction forces at small displacements (1–2 mm). Partial labral resection significantly decreased the distractive strength of the hip fluid seal. Labral reconstruction significantly improved distractive stability, compared to partial labral resection. The results of this study may provide insight into the relative importance of the capsule and labrum to distractive stability of the hip and may help to explain hip microinstability in the setting of labral disease.
Background
Detailed recognition of the three-dimensional (3-D) deformity in acetabular dysplasia is important to help guide correction at the time of reorientation during periacetabular osteotomy ...(PAO). Common plain radiographic parameters of acetabular dysplasia are limited in their ability to characterize acetabular deficiency precisely. The 3-D characterization of such deficiencies with low-dose CT may allow for more precise characterization.
Questions/purposes
The purposes of this study were (1) to determine the variability in 3-D acetabular deficiency in acetabular dysplasia; (2) to define subtypes of acetabular dysplasia based on 3-D morphology; (3) to determine the correlation of plain radiographic parameters with 3-D morphology; and (4) to determine the association of acetabular dysplasia subtype with patient clinical characteristics including sex, range of motion, and femoral version.
Methods
Using our hip preservation database, we identified 153 hips (148 patients) that underwent PAO from October 2013 to July 2015. Among those, we noted 103 hips in 100 patients with acetabular dysplasia (lateral center-edge angle < 20°) and who had a Tönnis grade of 0 or 1. Eighty-six patients (86%) underwent preoperative low-dose pelvic CT scans at our institution as part of the preoperative planning for PAO. It is currently our standard to obtain preoperative low-dose pelvic CT scans (0.75–1.25 mSv, equivalent to three to five AP pelvis radiographs) on all patients before undergoing PAO unless a prior CT scan was performed at an outside institution. Hips with a history of a neuromuscular disorder, prior trauma, prior surgery, radiographic evidence of joint degeneration, ischemic necrosis, or Perthes-like deformities were excluded. Fifty hips in 50 patients met inclusion criteria and had CT scans available for review. These low-dose CT scans of 50 patients with symptomatic acetabular dysplasia undergoing evaluation for surgical planning of PAO were then retrospectively studied. CT scans were analyzed quantitatively for acetabular coverage, relative to established normative data for acetabular coverage, as well as measurement of femoral version. The cohort included 45 females and five males with a mean age of 26 years (range, 13–49 years).
Results
Lateral acetabular deficiency was present in all patients, whereas anterior deficiency and posterior deficiency were variable. Three patterns of acetabular deficiency were common: anterosuperior deficiency (15 of 50 30%), global deficiency (18 of 50 36%), and posterosuperior deficiency (17 of 50 34%). The presence of a crossover sign or posterior wall sign was poorly predictive of the dysplasia subtype. With the numbers available, males appeared more likely to have a posterosuperior deficiency pattern (four of five 80%) compared with females (13 of 45 29%, p = 0.040). Hip internal rotation in flexion was significantly greater in anterosuperior deficiency (23° versus 18°, p = 0.05), whereas external rotation in flexion was significantly greater in posterosuperior deficiency (43° versus 34°, p = 0.018). Acetabular deficiency pattern did not correlate with femoral version, which was variable across all subtypes.
Conclusions
Three patterns of acetabular deficiency commonly occur among young adult patients with mild, moderate, and severe acetabular dysplasia. These patterns include anterosuperior, global, and posterosuperior deficiency and are variably observed independent of femoral version. Recognition of these distinct morphologic subtypes is important for diagnostic and surgical treatment considerations in patients with acetabular dysplasia to optimize acetabular correction and avoid femoroacetabular impingement.
Background:
Borderline acetabular dysplasia is commonly radiographically defined as a lateral center-edge angle (LCEA) of 20° to 25°. While the variability of plain radiographic assessment of this ...population has been reported, an understanding of the variability of 3-dimensional (3D) hip morphology remains to be better defined.
Purpose:
To investigate the variability of 3D hip morphology present on low-dose computed tomography (CT) in the setting of symptomatic borderline acetabular dysplasia and to determine if plain radiographic parameters correlate with 3D coverage.
Study Design:
Cohort study (diagnosis); Level of evidence, 2.
Methods:
A total of 70 consecutive hips with borderline acetabular dysplasia undergoing hip preservation surgery were included in the current study. Plain radiographic evaluation included LCEA, acetabular inclination, anterior center-edge angle (ACEA), anterior wall index (AWI), posterior wall index (PWI), and alpha angles on anteroposterior, 45° Dunn, and frog-leg views. All patients underwent low-dose pelvic CT for preoperative planning, which allowed detailed characterization of 3D morphology relative to normative data. Acetabular morphology was assessed with radial acetabular coverage (RAC) calculated according to standardized clockface positions from 8:00 (posterior) to 4:00 (anterior). Coverages at 10:00, 12:00, and 2:00 were classified as normal, undercoverage, or overcoverage relative to 1 SD from the mean of normative RAC values. Femoral morphology was assessed with femoral version, alpha angle (measured at 1:00 increments), and maximum alpha angle. Correlation was assessed with the Pearson correlation coefficient (r).
Results:
Lateral coverage (12:00 RAC) was deficient in 74.1% of hips with borderline dysplasia. Anterior coverage (2:00 RAC) was highly variable, with 17.1% undercoverage, 72.9% normal, and 10.0% overcoverage. Posterior coverage (10:00 RAC) was also highly variable, with 30.0% undercoverage, 62.9% normal, and 7.1% overcoverage. The 3 most common patterns of coverage were isolated lateral undercoverage (31.4%), normal coverage (18.6%), and combined lateral and posterior undercoverage (17.1%). The mean femoral version was 19.7°± 10.6° (range, −4° to 59°), with 47.1% of hips having increased femoral version (>20°). The mean maximum alpha angle was 57.2° (range, 43°-81°), with 48.6% of hips having an alpha angle ≥ 55°. The ACEA and AWI were poorly correlated with radial anterior coverage (r = 0.059 and 0.311, respectively), while the PWI was strongly correlated with radial posterior coverage (r = 0.774).
Conclusion:
Patients with borderline acetabular dysplasia demonstrate highly variable 3D deformities, including anterior, lateral, and posterior acetabular coverage; femoral version; and alpha angle. Plain radiographic assessments of anterior coverage are poorly correlated with anterior 3D coverage on low-dose CT.
Cam-type femoroacetabular impingement (FAI) is generally described as being more common in males, with pincer-type FAI being more common in females. The purpose of this study was to determine the ...effect of sex on FAI subtype, clinical presentation, radiographic findings, and intraoperative findings in patients with symptomatic FAI.
We compared cohorts of fifty consecutive male and fifty consecutive female patients who were undergoing surgery for symptomatic FAI. Detailed information regarding clinical presentation, radiographic findings, and intraoperative pathology was recorded prospectively and analyzed. FAI subtype was classified on the basis of clinical diagnosis and radiographic evaluation.
Female patients had significantly greater disability at presentation, as measured with use of the modified Harris hip score (mHHS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Hip Disability and Osteoarthritis Outcome Score (HOOS), and the SF-12 (12-Item Short Form Health Survey) physical function subscore (all p ≤ 0.02), despite a significantly lower UCLA (University of California at Los Angeles) activity score (p = 0.03). Female patients had greater hip motion (flexion and internal rotation and external rotation in 90° of flexion; all p ≤ 0.003) and less severe cam-type morphologies (a mean maximum alpha angle of 57.6° compared with 70.8° for males; p < 0.001). Males were significantly more likely to have advanced acetabular cartilage lesions (56% of males compared with 24% of females; p = 0.001) and larger labral tears with more posterior extension of these abnormalities (p < 0.02). Males were more likely than females to have mixed-type FAI and thus a component of pincer-type FAI (combined-type FAI) (62% of males compared with 32% of females; p = 0.003).
We found distinct, sex-dependent disease patterns in patients with symptomatic FAI. Females had more profound symptomatology and milder morphologic abnormalities, while males had a higher activity level, larger morphologic abnormalities, more common combined-type FAI morphologies, and more extensive intra-articular disease.
Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.
Purpose The purpose of this study was to investigate the prevalence of radiographic findings of femoroacetabular impingement (FAI) in elite football players with a history of hip pain or groin injury ...who underwent radiographs. Methods We performed a retrospective review of athletes undergoing hip radiography at the National Football League Combine from 2007 to 2009. Radiographs were obtained in athletes with a history of hip pain or injury. Anteroposterior pelvis and frog-lateral radiographs were obtained in 123 hips (107 players) that met our inclusion criteria. Radiographic indicators of cam-type FAI (alpha angle, head-neck offset ratio) and pincer-type FAI (acetabular retroversion, center-edge angle, acetabular inclination) were recorded. Findings were correlated with clinical factors (previous groin/hip pain, position, race, and body mass index). Results The most common previous injuries included groin strain (n = 57) and sports hernia/abdominal strain (n = 21). Markers of cam- and/or pincer-type FAI were present in 94.3% of hips (116 of 123). Radiographic evidence of combined cam- and pincer-type FAI was the most common (61.8%, 76 hips), whereas isolated cam-type FAI (9.8%, 12 hips) and pincer-type FAI (22.8%, 28 hips) were less common. The most common deformities included acetabular retroversion (71.5%) and an abnormal alpha angle (61.8%). A body mass index greater than 35 was associated with the presence of global overcoverage (46.2% v 17.3%, P = .025). Conclusions Radiographic indicators of FAI are very common among athletes evaluated at the National Football League Scouting Combine subjected to radiographic examination for the clinical suspicion of hip disease. Elite football athletes with significant or recurrent pain about the hip should be evaluated clinically and radiographically for FAI, because pain from FAI may be falsely attributed to or may be present in addition to other disorders. Level of Evidence Level IV, therapeutic case series.
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