Treatment Of Cam-type Femoroacetabular Impingement Research Articles

Genes associated with inflammation and bone remodeling are highly expressed in the bone of patients with the early-stage cam-type femoroacetabular impingement

BackgroundRecent studies have shown high expression levels of certain inflammatory, anabolic, and catabolic genes in the articular cartilage from the impingement zone of the hips with femoroacetabular impingement (FAI), representing an increased metabolic state. Nevertheless, little is known about the molecular properties of bone tissue from the impingement zone of hips with FAI.MethodsBone tissue samples from patients with early-stage cam-type FAI were collected during hip arthroscopy for treatment of cam-type FAI. Control bone tissue samples were collected from six patients who underwent total hip replacement because of a femoral neck fracture. Quantitative real-time polymerase chain reaction (PCR) was performed to determine the gene expression associated with inflammation and bone remodeling. The differences in the gene expression in bone tissues from the patients with early-stage cam-type FAI were also evaluated based on clinical parameters.ResultsIn all, 12 patients with early-stage cam-type FAI and six patients in the control group were included in this study. Compared to the control samples, the bone tissue samples from patients with FAI showed higher expression levels of interleukin-6 (IL-6), alkaline phosphatase (ALP), receptor activator of nuclear factor-kB ligand (RANKL), and osteoprotegerin (OPG) (P < 0.05). IL-1 expression was detected only in the control group. On the other hand, there was no significant difference in IL-8 expression between the patients with FAI and the control group. The patients with FAI having a body mass index (BMI) of >24 kg/m2 showed higher ALP expression (P < 0.05). Further, the expression of IL-6 and ALP was higher in the patients with FAI in whom the lateral center-edge angle was >30° (P < 0.05).ConclusionsOur results indicated the metabolic condition of bone tissues in patients with early-stage cam-type FAI differed from that of normal bone in the femoral head-neck junction. The expression levels of the genes associated with inflammation and bone remodeling were higher in the bone tissue of patients with early-stage cam-type FAI than in the patients with normal bone tissue.

The Effect of Resection Size in the Treatment of Cam-Type Femoroacetabular Impingement in the Typical Patient With Hip Arthroscopy: A Biomechanical Analysis

Background: Arthroscopic osteochondroplasty may improve range of motion and relieve pain in patients with symptomatic hip impingement. Femoral neck fracture is a risk of this procedure because of the weakening of the proximal femur. To our knowledge, there are no biomechanical studies in young human cadaveric bone evaluating the effect of osteochondroplasty on femoral neck strength. Purpose/Hypothesis: The purpose was to evaluate loads to fracture in young human cadavers after resection depths of 25% and 40% at the head-neck junction. We hypothesized that both depths will maintain ultimate loads to failure above previously published loads, as well as above physiologic weightbearing loads. Study Design: Descriptive laboratory study. Methods: Cadaveric proximal femoral specimens (6 matched pairs, under the age of 47 years) were divided into 2 groups: 25% or 40% of the diameter at the head-neck junction was resected. The length of the resection was 2 cm and the width of the resection was determined by the length of the anterolateral quadrant at the head-neck junction in all cases. A compressive load was applied directly to the femoral head. Peak load, stiffness, and energy to fracture were compared between groups. Results: The average peak load to fracture after 25% resection (7347 N) was significantly higher than after the 40% resection (5892 N) (P = .010). The average energy to fracture was also significantly higher in the 25% resection group (30.2 J vs 19.2 J; P = .007). The average stiffness was higher in the 25% group, although not statistically significant (P = .737). Conclusion: Resection depths of 25% and 40% at the anterolateral quadrant of the femoral head-neck junction may be safe at previously described functional loads such as standing and walking in the age range more typically seen in patients undergoing hip arthroscopy. Loads to fracture were significantly higher than previously reported using older cadaveric specimens. Clinical Relevance: Currently, most surgeons limit weightbearing after femoral osteochondroplasty in part because of risk of femoral neck fracture. Given the higher observed loads to fracture, young patients could possibly bear weight sooner after surgery, although postoperative protocols should be individualized based on patient age, weight, bone density, amount of bone resected, concomitant procedures, and potential compliance with activity restrictions.

Hip Arthroscopy for Cam-type Femoroacetabular Impingement

Cam deformity represents a common cause of femoroacetabular impingement (FAI) syndrome, a disorder that can result in irreversible damage to the labrum and articular cartilage and accelerate hip degeneration. Workup must include a thorough evaluation with physical exam, radiographs, MRI, and 3D CT imaging to appropriately characterize impingement and plan appropriate surgical correction. Surgical management with arthroscopic femoral head-neck osteochondroplasty can alleviate femoral bony impingement and is often performed alongside other arthroscopic procedures to the labrum, articular cartilage, and other sources of impingement including the acetabular rim and subspine. Intraoperative fluoro should be used extensively to identify the extent of the deformity and appropriately correct femoral head-neck offset while maintain head-neck sphericity without over-resecting the femoral neck . We review relevant literature and the senior authors preferred technique for arthroscopic treatment of cam-type femoroacetabular impingement.

Arthroscopic treatment of Cam-type femoroacetabular impingement

Femoroacetabular impingement (FAI) is a common cause of hip pain and limited range of motion among young and middle-aged active adults and athletes. The acetabular labral tear and cartilage damage secondary to FAI may increase the risk of hip osteoarthritis. FAI is characterized by pathologic impact between the femoral headneck junction and the acetabular rim secondary to bony deformity. According to the pathological anatomy leading to impingement, the FAI can be divided into the femoral cam-type deformity (Cam), the acetabular over-coverage deformity (Pincer) and a combination of both. In recent years, arthroscopic osteoplasty of the femoral head-neck junction is the main way to treat the Cam deformity; However, there still remain some controversies about how to perform an adequate and effective arthroscopic femoroplasty. Based on this problem, the present article reviewed the preoperative diagnosis, intraoperative evaluation, surgical techniques and postoperative evaluation of Cam-type FAI to explore how to adequately correct Cam deformity under arthroscopy. In the present study, a total of 1928 related articles were obtained by searching PubMed, Web of Science, Cochrane library, China Knowledge Network, Wanfang Full-text Database and Weipu Science and Technology Journal Database. According to the inclusion and exclusion criteria, 43 papers were finally included. After summarizing the above literatures, it was found that anatomical structures such as Cam deformity, femoral neck anteversion, and acetabular coverage can be evaluated preoperatively by X-ray, three-dimensional CT and MRI. X-ray fluoroscopy and arthroscopic dynamic examination are performed during the femoroplasty to locate the Cam deformity and to determine whether the femoral neck offset radio and the spherical structure of femoral head are corrected, at the same time, it is necessary to consider the overall anatomy of the hip joint to achieve an adequate resection of the Cam deformity and restore the normal mobility of the hip joint.

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.

Quantitative Assessment of Femoral Head Perfusion Following Arthroscopic Femoral Osteochondroplasty: A Cadaveric Study.

Disruption of the arterial supply to the femoral head, and subsequent development of femoral head osteonecrosis, is of serious concern with intracapsular hip procedures. However, the effect of arthroscopic femoral osteochondroplasty on femoral head perfusion is unknown. We aimed to quantify the effects of both standard and posterosuperior extension of arthroscopic femoral osteochondroplasty on femoral head vascularity. We hypothesized that extension of the superior resection zone posteriorly would negatively affect femoral head perfusion. In 12 cadaveric pelvic specimens, we cannulated the medial femoral circumflex artery (MFCA). One hip per pelvis was randomly selected to be in 1 of 2 experimental groups based on the superior extent of the osteochondroplasty: standard resection (resection anterior to the 12 o'clock [0° of 360°] position) or extended resection (resection extended posterior to the 12 o'clock position). Computed tomography (CT) scans were obtained prior to and following arthroscopic resection to delineate the resection margins. Gadolinium enhancement on magnetic resonance imaging (MRI) was quantified in the femoral head by volumetric analysis using custom software. A polyurethane compound was injected and gross dissection of the vasculature was performed. Extension of the osteochondroplasty posteriorly (the extended-resection group), to a mean of 41.3° (range, 34° to 47°) posterior to the 12 o'clock position, decreased femoral head perfusion by a mean of 28% (range, 18% to 38%). The standard-resection group demonstrated a mean decrease in femoral head perfusion of 7% (range, 4% to 11%). Correlation analysis demonstrated a significant negative correlation (correlation coefficient, -0.877; p < 0.001; R = 0.747). For every 1° that the superior resection margin extended posteriorly, a corresponding 0.88% decrease in femoral head perfusion was found. Femoral head perfusion is almost fully maintained with arthroscopic osteochondroplasty when the superior resection margin is anterior to the 12 o'clock position. Perfusion is also well maintained if the superior resection margin is extended no more than 10° posterior to 12 o'clock. Further posterior extension correlated with greater decreases in femoral head perfusion. Our study provides previously unreported quantitative MRI data on femoral head perfusion following arthroscopic femoral osteochondroplasty for the treatment of cam-type femoroacetabular impingement.

Robotic-assisted femoral osteochondroplasty is more precise than a freehand technique in a Sawbone model.

Robotic-assistance has the potential to improve the accuracy of bony resections, when performing femoral osteochondroplasty in the treatment of cam-type femoroacetabular impingement (FAI). The purpose of this study was to determine the accuracy of robotic-assisted femoral osteochondroplasty and compare this to a conventional open, freehand technique. We hypothesized that robotic-assistance would increase the accuracy of femoral head-neck offset correction in cam FAI. Sixteen identical sawbones models with a cam-type impingement deformity were resected by a single surgeon, simulating an open femoral osteochondroplasty. Eight procedures were performed using an open freehand technique and eight were performed using robotic-assistance, through the creation of a three-dimensional haptic volume. A desired arc of resection of 117.7° was determined pre-operatively using an anatomic plan. Post-resection, all 16 sawbones were laser scanned to measure the arc of resection, volume of bone removed and depth of resection. For each sawbone, these measurements were compared with the pre-operatively planned desired resection, to determine the resection error. Freehand resection resulted in a mean arc of resection error of 42.0 ± 8.5° compared with robotic-assisted resection which had a mean arc of resection error of 1.2 ± 0.7° (P < 0.0001). Over-resection occurred with every freehand resection with a mean volume error of 758.3 ± 477.1 mm3 compared with a mean robotic-assisted resection volume error of 31.3 ± 220.7 mm3 (P < 0.01). This study has shown that robotic-assisted femoral osteochondroplasty in the treatment of cam-type FAI is more accurate than a conventional, freehand technique, which are currently in widespread use.

Treatment of cam-type femoroacetabular impingement.

the aim of this study was to evaluate preliminary clinical and radiographic results of arthroscopic treatment of cam-type femoroacetabular impingement (FAI). thirty-eight patients underwent hip arthroscopy for cam-type FAI between 2009 and 2012. Preoperative assessment was based on clinical examination, modified Harris Hip Score (mHHS) and radiographic examination with anteroposterior pelvis, frog-leg and Lequesne views. The patients' clinical conditions at follow-up were assessed using the mHHS administered as a telephone survey. Radiographic outcome measurements evaluated pre and postoperatively were the alpha angle and femoral head-neck offset. the patients were clinically evaluated at a mean follow-up of 36 months. Radiographic follow-up was performed at an average of 12.7 months. Thirty of the 38 patients (79%) were satisfied with the results of the arthroscopic procedure. A total of nine patients subsequently underwent a total hip replacement. All 30 patients who declared themselves satisfied recorded an mHHS increase; in particular, the mHHS increased from a mean of 52.9 preoperatively (range: 27.5-82.5) to a mean of 85.6 postoperatively (range: 45.1-100.1). Three significant differences between the two groups of patients (satisfied and not satisfied) were recorded: mean age, alpha angle and BMI were all significantly greater in the patients who were not satisfied with the treatment. a crucial aspect in order to obtain good clinical outcomes of arthroscopic treatment of cam-type impingement is correct selection of patients who are likely to benefit from this kind of surgery. Hip arthroscopy should be avoided in patients aged over 50 years with risk factors for early osteoarthritis (high BMI and a significantly increased alpha angle). Level IV, therapeutic case series.

Ultrasonography can quantify the extent of osteochondroplasty after treatment of Cam-type femoroacetabular impingement

Surgical resection of femoroacetabular Cam impingement (cam-FAI) is now a generally accepted treatment, producing adequate hip score increases. Insufficient resection at the head-neck junction is the main reason for revision. The anterolateral region of the head-neck junction is visualized only suboptimally by radiography, which can be inadequate for monitoring resection results postoperatively. Our aim was to investigate the extent of Cam resection by ultrasonography (US) and determine if there is any correlation with clinical outcome. Altogether, 40 consecutive patients (mean age 39 years) were enrolled in this prospective study following arthroscopic Cam resection. All patients underwent standardized US examination in the ventral longitudinal section at 20° external rotation, neutral position, and 20° internal rotation the day before arthroscopy and two days afterward. Alpha angle, anterior offset, offset ratio, and anterior femoral distance were measured on sonograms. Hip Disability and Osteoarthritis Outcome Score (HOOS) and Western Ontario and McMaster University Index of Osteoarthritis (WOMAC) were conducted the day before surgery and 6 weeks postoperatively (at the earliest). Alpha angle was significantly smaller on postoperative US in all hip joint positions. At 20° internal rotation, the alpha angle decreased from 65.6 to 36.9° (p < 0.0001). All but two (5%) patients had alpha angles <50°. Anterior offset increased significantly on US in neutral position and at 20° internal rotation. HOOS and WOMAC increased significantly. No correlation was found between measurements for Cam-FAI and the scores. US may be a useful tool for monitoring Cam-FAI resection results postoperatively.

Is early treatment of cam-type femoroacetabular impingement the key to avoiding associated full thickness isolated chondral defects?

Hip arthroscopy is a safe and reproducible method for treating femoroacetabular impingement (FAI) and has evolved greatly in recent years. But little is known about the influences on the outcome after surgery. The aims of the current study were to elucidate (1) which parameters can be used as a marker for the presence of chondral and labral lesions, (2) the postoperative clinical outcome, and (3) at which time after surgery recovery occurs. A prospective study was performed with 177 patients who underwent hip arthroscopy because of cam-type FAI. The patients were examined preoperatively as well as 6weeks and 6months postoperatively, and their condition was rated according to the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the Non-Arthritic Hip Score (NAHS). Statistical analyses were performed to evaluate the influence of independent factors such as "patient age," "pain duration before surgery" on the clinical outcome, and the appearance of chondral or labral defects. The NAHS and WOMAC scores showed a significant enhancement 6weeks after surgery. Only the NAHS showed a further improvement after 6months. A positive correlation with the dependent variable "chondral lesion" was evaluated for the independent variables "pain duration before surgery," "preoperative NAHS," and "labrum lesion". Using ROC analysis, the optimal cutoff value of "pain duration before surgery" as a predictor was 9.5months, for the NAHS 42.5 points. For the dependent variable, "6-month postoperative NAHS" significant correlations for the independent variables "age" and "pain duration before surgery" were revealed with a cutoff value of 55.5years, respectively, 23.5months. It was concluded from the results that the date of surgery is relevant for the appearance of chondral defects. Patient age is a further relevant factor for clinical outcome. Recovery after hip arthroscopy takes place mainly in the first 6weeks after surgery. Therapeutic study, Level III.

Intraoperative Fluoroscopic Imaging to Accurately Treat Cam Deformities: Correlation with 3D Computed Tomography

In the diagnosis and surgical treatment of cam-type femoroacetabular impingement (FAI), three-dimensional (3D) imaging is the gold standard for detecting and defining femoral head-neck junction malformations. Although intraoperative fluoroscopy is used by many surgeons to evaluate and verify adequate correction of the deformity, a meaningful, systematic approach has not been well defined. The purposes of this study were (1) to correlate radial reformatted computed tomography (CT) scans with six defined intraoperative fluoroscopic views prior to surgical correction to determine if fluoroscopy could adequately depict cam deformity, and (2) to define the influence of femoral version on the clock-face location of the maximum cam deformity on these views. A consecutive series of 50 hips (48 patients) that underwent arthroscopic treatment for symptomatic FAI by a single surgeon were analyzed. Each patient underwent a CT scan and six consistent intraoperative fluoroscopy views: three views in hip extension (medial and lateral deformities) and three views in hip flexion of 50° (anterior and posterior deformities). The alpha angles of each of the fluoroscopic images were correlated with the radial reformatted CT using a 3D software program. Femoral version was also assessed on CT studies. Statistical analysis was performed with Student's t-test, with P < .05 defined as significant. Fifty-two percent of patients were male, average age of 28 years (range, 15-56 years). The maximum mean alpha angle was 65° (range, 37°–93°) and was located on the anteroposterior (AP) 30° external rotation (ER) fluoroscopy view. The mean clock-face positions of each of the fluoroscopy views (standardized to the right hip) were AP 30° internal rotation, 11:45; AP 0° (neutral) rotation, 12:30; AP 30° ER, 1:00; flexion/0° (neutral) rotation, 1:45; flexion/40° ER, 2:15; and flexion/60° ER, 2:45. Increased femoral anteversion (>20°) was associated with a significant change in the location of the maximum alpha angle (1:45 vs. 1:15; P = .002). The described six fluoroscopic views are helpful in localization and visualization of the typical cam deformity from 11:45 to 2:45 and can be utilized to reliably confirm a complete intraoperative resection of cam-type deformity in most patients. These views correlate with preoperative 3D imaging, and may be of even greater importance in the absence of preoperative 3D imaging.

Intraoperative Fluoroscopic Imaging to Treat Cam Deformities

Background: In the diagnosis and surgical treatment of cam-type femoroacetabular impingement (FAI), 3-dimensional (3D) imaging is the gold standard for detecting femoral head-neck junction malformations preoperatively. Intraoperative fluoroscopy is used by many surgeons to evaluate and verify adequate correction of the deformity. Purpose: (1) To compare radial reformatted computed tomography (CT) scans with 6 defined intraoperative fluoroscopic views before surgical correction to determine whether fluoroscopy could adequately depict cam deformity, and (2) to define the influence of femoral version on the clock-face location of the maximum cam deformity on these views. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: A consecutive series of 50 hips (48 patients) that underwent arthroscopic treatment for symptomatic FAI by a single surgeon were analyzed. Each patient underwent a CT scan and 6 consistent intraoperative fluoroscopy views: 3 views in hip extension and 3 views in hip flexion of 50°. The alpha angles of each of the fluoroscopic images were compared with the radial reformatted CT using a 3D software program. Femoral version was also defined on CT studies. Statistical analysis was performed using the Student t test, with P < .05 defined as significant. Results: Fifty-two percent of patients were male, average age 28 years (range, 15-56 years). The maximum mean alpha angle on fluoroscopy was 65° (range, 37°-93°) and was located on the anteroposterior (AP) 30° external rotation (ER) fluoroscopy view. In comparison, the mean CT-derived maximum alpha angle was 67° and was located at 1:15 (P = .57). The mean clock-face positions of each of the fluoroscopy views (standardized to the right hip) were AP 30° internal rotation, 11:45; AP 0° (neutral) rotation, 12:30; AP 30° ER, 1:00; flexion/0° (neutral) rotation, 1:45; flexion/40° ER, 2:15; and flexion/60° ER, 2:45. Increased femoral anteversion (>20°) was associated with a significant change in the location of the maximum alpha angle (1:45 vs 1:15; P = .002). Conclusion: The described 6 fluoroscopic views are very helpful in localization and visualization of the typical cam deformity from 11:45 to 2:45 and can be used to reliably confirm a complete intraoperative resection of cam-type deformity in most patients. These views correlate with preoperative 3D imaging and may be of even greater importance in the absence of preoperative 3D imaging.

English

Delaminated acetabular cartilage is a common finding in patients undergoing surgical dislocation or hip arthroscopy in the treatment of cam-type femoroacetabular impingement. Current treatment involves resection of the free cartilage flap with or without acetabular rim trimming. The viability of the delaminated cartilage flap is not known. We sought to examine if the acetabular cartilage still has viable cartilage cells and, if so, what type of cartilage is present. We examined the delaminated cartilage flaps from patients undergoing surgical dislocation and osteochondroplasty for symptomatic cam-type impingement. We performed hematoxylin and eosin staining and histological analysis using light microscopy to determine cartilage viability and cartilage type. We examined 12 delaminated cartilage flaps from 11 patients (10 men, 1 woman, average age 30.1 yr). Ninety percent chondrocyte viability was confirmed in 11 of 12 flaps. Six of 12 flaps were composed predominantly of hyaline cartilage, 4 were a mixed population of fibrocartilage and hyaline cartilage and 2 were predominantly fibrocartilage. Our findings suggest that the delaminated cartilage flap in patients with femoroacetabular impingement may retain a large amount of viable chondrocytes. Development of surgical techniques focusing on refixation of this flap as an alternative to excision and microfracture should be considered.

Retrospective Evaluation of Femoral Osteoplasty And Labral Debridement in Cam-Type Femoroacetabular Impingement Patients—An Average Followup of 5 Years (SS-38)

Femoroacetabular impingement (FAI) has been increasingly recognized as a source of primary hip pathology and has been associated with early onset degenerative hip disease. Cam-type impingement can create shear stress at the acetabular rim, causing chondral delamination and articular-sided labral degeneration. The purpose of this study is to evaluate the clinical outcomes of arthroscopic treatment of cam-type femoroacetabular impingement. Ninety-four consecutive patients (100 hips) with cam impingement underwent arthroscopic femoral neck osteoplasty and labral debridement. Eighty-two hips (82%) were contacted and available for followup at a mean of 60 months (range, 40-74). Patients were assessed with preoperative and postoperative physical examination, nonarthritic hip score (NAHS), Western Ontario and McMasters Universities (WOMAC) score, and radiographs to assess the Tonnis Grade for osteoarthritis and alpha-angle. Postoperative evaluation included pain score assessment with a visual analog scale and satisfaction assessment. Eighty-two hips were contacted for followup evaluation. There were 54 patients who had not undergone additional surgeries. Six patients required revision hip arthroscopies. Twenty-two patients underwent hip arthroplasty, summing up to an overall revision rate of 28%. Of the patients who had not undergone revision surgeries, the mean NAHS rose from 48.9 to 78 and the WOMAC increased from 66.8 to 77. Patient satisfaction was 70 percent. Twenty-five of the 54 hips were available for clinical evaluation. Presence of internal rotation impingement sign decreased from 92.6 to 37.5 percent. Repeat radiograph showed improved alpha angles from 76.8 to 61.6 degrees. Of the patients with pre-existing osteoarthritis (Tonnis Grade 2-3), 84.6% went on to require hip arthroplasty. Of the patients with minimal to no pre-existing osteoarthritis (Tonnis Grade 0-1), 16.4% went on to require hip arthroplasty. Arthroscopic femoral neck resection in patients with cam-type FAI results in improved clinical outcomes, decreased physical symptoms, and a high patient satisfaction at a mean followup of 5 years. In the subset of patients with pre-existing osteoarthritis, there is high risk of needing an arthroplasty procedure within 5 years.

Influence of Resection Geometry on Fracture Risk in the Treatment of Femoroacetabular Impingement

Background: A fracture is the most serious complication of surgical resection of the femoral head-neck junction in the treatment of cam-type femoroacetabular impingement (FAI). Purpose: To investigate the influence of resection length, width, and depth on postoperative fracture risk in activities of daily living. Study Design: Descriptive laboratory study. Methods: The femoral anatomy used for the finite element model was based upon a publicly available standardized model. For descriptive validation, the fracture location was compared with radiographs of patients who had suffered from a femoral neck fracture after surgical treatment of FAI in our institution. Additionally, a 2-part quantitative validation against previously published experimental data was performed. To simulate surgery, round resections were made in which length and width were varied at 10%, 20%, and 30%. The fracture loads were compared with published in vivo loads measured during activities of daily living with telemetric hip implants. Results: Validation showed that the model predicted fracture locations comparable with clinical cases and fracture loads within published experimental values. Femoral fracture loads were 325% more sensitive to resection deepening and 70% more sensitive to widening than lengthening. Conclusion: Although resection depth is the most important determinant of bone resistance, it should be considered in combination with resection length and width. Even a resection depth as low as 10% may lead to a fracture in case of stumbling. Clinical Relevance: We show that for resection depths of 20% or less and resection length of less than 35% of the femoral neck, normal activities of daily living are safe. Resection widths typically achieved in practice did not induce fractures during activities of daily living. Patients who have undergone surgical resection should be counseled on how to try to avoid stumbling.

Paper 4: Arthroscopic Treatment Cam-Type Hip Impingement Lesions with 32.8-Month Mean Follow-Up

Paper 4: Arthroscopic Treatment Cam-Type Hip Impingement Lesions with 32.8-Month Mean Follow-Up

Combined Arthroscopic and Mini-Open Treatment of CAM-Type Femoroacetabular Impingement

ABSTRACT Purpose Osteochondroplasty of the femoral head-neck junction can improve hip pain and function in patients with femoroacetabular impingement. We report our initial series of patients undergoing surgical treatment for symptomatic CAM type femoroacetabular impingement using a combined arthroscopic and mini-open approach. Materials and methods A retrospective chart review of 20 consecutive patients was performed. Seventeen patients had adequate follow-up for inclusion. Preoperative clinical and radiographic characteristics as well as intraoperative findings were obtained from patient records. Postoperative Harris Hip scores and VAS pain scores were recorded at final follow-up. Results At an average of 27.8 months (range 12-48 months), the mean Harris Hip score improved from 64.7 preoperatively to 86.8 (p &lt; 0.001). The mean VAS pain score improved from 4.80 to 1.53 (p = 0.001). Two patients (11.7%) underwent total hip arthroplasty at an average of 15 months postoperatively. Fourteen patients (82%) stated they would have the procedure again. There were no significant complications. Conclusion Surgical treatment of CAM type femoroacetabular impingement using a combined arthroscopic and mini-open anterior hip approach has a low complication rate and improves functional and pain scores at short-term follow-up. Watters TS, Kaufman AM, Solic JM, Stinnett SS, Olson SA. Combined Arthroscopic and Mini-Open Treatment of CAM-Type Femoroacetabular Impingement. The Duke Orthop J 2012;2(1):60-65.

Distance Between Femoral Bump and Retinacular Vessels in Cam-Type Femoroacetabular Impingement (SS-43)

Introduction The complete resection of the femoral bump is essential in the treatment of cam-type femoroacetabular impingement (FAI). The lesion of the retinacular vessels is possible during the resection of the most lateral portion of the femoral bump. The purpose of this study is the measurement of the distance between the femoral bump resection and the entry point of the retinacular vessels into the femoral head. Methods During a one-year period (October 2007-2008) we performed a CTscan with 3-D reconstruction in 60 patients with Cam-type FAI (34 males, 26 females, mean age 36, 5 years) before and after arthroscopic resection of the femoral bump. We identified the foraminas, corresponding to the entry point of the retinacular vessels into the femoral head. During the arthroscopy the retinacular vessels were identified prior to the bump resection. One year after hip-arthroscopy a clinical evaluation was realized to exclude avascular necrosis (AVN) of the femoral head. Results The mean distance between the most anterior foramina to the lateral limit of the femoral bump was 6.1 mm (1.1mm-17 mm). In the clinical evaluation 1 year after arthroscopy no patient presented with clinical signs suggesting AVN of the femoral head. Conclusion A CTscan with 3-D reconstruction helps to identify the lateral limit of the femoral bump and the entry point of the retinacular vessels into the femoral head. Because the lateral limit of the femoral bump extends close to the retinacular vessels, we recommend arthroscopic visualization of these vessels prior to the resection of the lateral portion of the femoral bump.

Arthroscopic Femoroplasty in the Management of Cam-type Femoroacetabular Impingement

Cam-type femoroacetabular impingement is a recognized cause of intraarticular pathology and secondary osteoarthritis in young adults. Arthroscopy is reportedly useful to treat selected hip abnormalities and has been proposed as a method of correcting underlying impingement. We report the outcomes of arthroscopic management of cam-type femoroacetabular impingement. We prospectively assessed all 200 patients (207 hips) who underwent arthroscopic correction of cam impingement from December 2003 to October 2007, using a modified Harris hip score. The minimum followup was 12 months (mean, 16 months; range, 12-24 months); no patients were lost to followup. The average age was 33 years with 138 men and 62 women. One hundred and fifty-eight patients (163 hips) underwent correction of cam impingement (femoroplasty) alone while 42 patients (44 hips) underwent concomitant correction of pincer impingement. The average increase in Harris hip score was 20 points; 0.5% converted to THA. We had a 1.5% complication rate. The short-term outcomes of arthroscopic treatment of cam-type femoroacetabular impingement are comparable to published reports for open methods with the advantage of a less invasive approach.

Arthroscopic Treatment of Cam-Type Femoroacetabular Impingement: Preliminary Report at 2 Years Minimum Follow-Up

Femoroacetabular impingement is defined as anterior hip abutment between the acetabular rim and proximal femur. When it is secondary to acetabular overcoverage, it is pincer impingement. When it is secondary to femoral head and neck deformity, it is cam impingement. Open remodeling of impinging deformities is the standard treatment of this condition. We describe arthroscopic treatment of cam impingement in 19 patients using standard hip arthroscopy portals by the lateral approach. Sixteen patients improved their symptoms after the procedure; and 3 patients deteriorated, with 1 needing a total hip arthroplasty at 2 years follow-up. We had no cases with postoperative femoral neck fractures or avascular necrosis. Hip arthroscopy can be successfully used to treat cam impingement. The precautions used in open surgery to preserve femoral neck bone stock and hip vascularity should be followed.