Jon E. Hammarstedt

Concomitant Hip Arthroscopy and Periacetabular Osteotomy

PURPOSE To detail our early experience using concomitant hip arthroscopy and periacetabular osteotomy (PAO) for the treatment of acetabular dysplasia. METHODS We prospectively collected and retrospectively reviewed the surgical and outcome data of 17 patients who underwent concomitant hip arthroscopy and PAO between October 2010 and July 2013. Preoperative and postoperative range of motion, outcome and pain scores, and radiographic data were collected. Intraoperative arthroscopic findings and postoperative complications were recorded. RESULTS The group consisted of 3 male and 14 female patients with a mean follow-up period of 2.4 years. Three patients had undergone previous surgery on the affected hip. Chondrolabral pathology was identified in all 17 patients. Twelve patients underwent labral repair, and five patients underwent partial labral debridement. No patient was converted to total hip arthroplasty or required revision surgery at short-term follow-up. All 4 patient-reported outcome scores showed statistically significant changes from baseline to latest follow-up (P < .001). An excellent outcome was obtained in 82% of patients (13 of 16). The lateral center-edge angle averaged 11° preoperatively and 29° postoperatively. The acetabular inclination averaged 18° preoperatively and 3° postoperatively. The anterior center-edge angle averaged 7° preoperatively and 27° postoperatively. At most recent radiographic follow-up, 1 patient had progression of arthritic changes but remained asymptomatic. No other patient showed any radiographic evidence of progression of arthritis. Complications included 3 superficial wound infections, 1 pulmonary embolism, and 1 temporary sciatic neurapraxia. CONCLUSIONS Our initial experience with concomitant hip arthroscopy and PAO has been favorable. We noted that all our patients have evidence of chondrolabral damage at the time of PAO when the joint is distracted and evaluated. All patients in this series had intra-articular pathology treated arthroscopically and showed satisfactory mean clinical improvement. Hip arthroscopy with PAO did not appear to introduce complications beyond the PAO alone. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Does Obesity Affect Outcomes in Hip Arthroscopy? A Matched-Pair Controlled Study With Minimum 2-Year Follow-up

Background: Hip arthroscopy has gained popularity over the past decade, and its indications have broadened as newer techniques have been developed. However, there has been a paucity of literature evaluating the outcomes of hip arthroscopy in obese patients. Purpose: To compare 2-year clinical outcomes of obese patients undergoing primary hip arthroscopy with matched nonobese controls. Study Design: Cohort study; Level of evidence, 3. Methods: From February 2008 to February 2012, data were collected prospectively on all obese patients undergoing primary hip arthroscopy. A matched-pair nonobese control group was selected at a 1:2 ratio. All patients were assessed pre- and postoperatively with 4 patient-reported outcome (PRO) measures: the modified Harris Hip Score, Non-Arthritic Hip Score, Hip Outcome Score–Activities of Daily Living, and Hip Outcome Score–Sport Specific Subscale. Pain was estimated on the visual analog scale, and satisfaction was measured on a scale from 0 to 10. Results: Sixty-two hips (62 patients) were included in the obese group and 124 hips (124 patients) in the control group. At preoperative baseline, the obese group had significantly lower PRO scores when compared with the control group. Both groups demonstrated statistically significant postoperative improvement in all scores (P < .05). Absolute scores were significantly lower in the obese group for all PRO measures, pre- and postoperatively. However, the improvement (delta) in PRO scores from pre- to postoperative time was not significantly different between groups. The rate of conversion to total hip arthroplasty, the rate of revision, and the complication rate were not significantly different between the 2 groups; however, rates of conversion to total hip arthroplasty and revision tended to be twice as high in the obese patients, but the study was not powered for these 2 outcomes. Conclusion: Overall, obese patients had lower absolute PRO scores preoperatively and at 2-year follow-up. Both obese and nonobese patients demonstrated significant improvement in all PRO scores, and the change in scores were similar between groups. These results indicate that while obese patients may not have similar absolute scores after hip arthroscopy, they may show similar gains in improvement when compared with baseline. Hip arthroscopy appears to be a viable treatment option in the obese patient as long as expectations are adjusted accordingly.

Does obesity affect outcomes after hip arthroscopy? A cohort analysis.

BACKGROUND Obesity presents a challenging problem in surgical treatment and has led to poorer postoperative outcomes. The purpose of this study was to evaluate whether hip arthroscopy in the obese patient influences postoperative clinical and patient-reported outcome scores. METHODS From February 2008 to February 2012, data were collected prospectively on all patients undergoing primary hip arthroscopy. A total of 680 patients were included. All patients were assessed preoperatively and postoperatively with four patient-reported outcome measures. Pain was estimated on the visual analog scale. The patient satisfaction score was measured. Three groups were stratified by body mass index. The non-obese group, those with a body mass index of <30 kg/m(2) (mean, 23.61 kg/m(2)), included 562 patients with a mean age of 34.78 years. The class-I obese group, those with a body mass index of ≥30 to 34.9 kg/m(2) (mean, 33.85 kg/m(2)), included ninety-four patients with a mean age of 44.02 years. The class-II obese group, those with a body mass index of ≥35 to 39.9 kg/m(2) (mean, 39.11 kg/m(2)), included twenty-four patients with a mean age of 39.33 years. RESULTS In the non-obese group, the score improvement from the preoperative assessment to the two-year follow-up visit was 63.41 to 83.81 points for the modified Harris hip score, 60.86 to 83.62 points for the Non-Arthritic Hip Score, 66.24 to 86.24 points for the Hip Outcome Score Activities of Daily Living, and 44.01 to 73.26 points for the Hip Outcome Score Sport-Specific Subscale. In the class-I obese group, the score improvement from the preoperative assessment to the two-year follow-up visit was 54.81 to 75.95 points for the modified Harris hip score, 48.98 to 72.51 points for the Non-Arthritic Hip Score, 53.22 to 72.99 points for the Hip Outcome Score Activities of Daily Living, and 30.56 to 60.75 points for the Hip Outcome Score Sport-Specific Subscale. In the class-II obese group, the score improvement from the preoperative assessment to the two-year follow-up visit was 50.81 to 80.01 points for the modified Harris hip score, 42.36 to 72.50 points for the Non-Arthritic Hip Score, 48.11 to 74.73 points for the Hip Outcome Score Activities of Daily Living, and 28.25 to 62.56 points for the Hip Outcome Score Sport-Specific Subscale. Traction time did not vary significantly between groups (p < 0.05). CONCLUSIONS Our study demonstrated that obese patients started with lower absolute scores preoperatively and ended with lower overall absolute postoperative scores. However, obese patients showed substantial benefit from hip arthroscopy and demonstrated a degree of improvement that was similar to that of the control non-obese group.

Arthroscopic Labral Reconstruction of the Hip Using Local Capsular Autograft

Labral reconstruction is becoming an important treatment modality for hips with nonsalvageable labra. Nonsalvageable labra can be present in cases of intrasubstance damage, revision surgery after debridement, labral calcification, and hypoplasia. Previous methods of reconstruction have been performed in an open manner and arthroscopically using ligamentum teres, iliotibial band, and gracilis autograft. We present an alternate method of arthroscopic labral reconstruction using capsular autograft. The technique uses readily available capsular tissue during arthroscopy with no donor-site morbidity. This technique may be valuable in appropriately selected patients with labral deficiency.

The learning curve associated with robotic-assisted total hip arthroplasty.

There are no reports examining the learning curve during the adoption of robotic assisted THA. The purpose of this study was to examine the learning curve of robotic assisted THA as measured by component position, operative time, and complications. The first 105 robotic-assisted THAs performed by a single surgeon were divided into three groups based on the order of surgery. Component position, operative time, intra-operative technical problems, and intra-operative complications were recorded. There was a decreased risk of acetabular component malpositioning with experience (P<0.05). Operative time appeared to decrease with increasing surgical experience (P<0.05). A learning curve was observed, as a decreased incidence of acetabular component outliers and decreased operative time were noted with increased experience.

Does Labral Size Correlate With Degree of Acetabular Dysplasia

Background: Hip dysplasia has been shown to be a cause of early arthritis. The decrease in bony coverage has shown increased stress on the acetabular labrum as it shares an increased load. Purpose/Hypothesis: The purpose of this study was to divide a cohort of patients by radiographic measures of dysplastic and nondysplastic hips for comparison with regard to labral size at 4 anatomic locations. The hypothesis was that dysplastic hips will have significantly larger labral size compared with nondysplastic hips. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A prospective study was conducted at a single institution. A total of 130 patients underwent hip arthroscopy during the study period from September 2011 to February 2012. Intraoperatively, arthroscopic measurements were taken at 4 quadrants on the acetabular clockface: anterosuperior (12-3 o’clock), anteroinferior (3-6 o’clock), posterosuperior (9-12 o’clock), and posteroinferior (6-9 o’clock). Three radiographic parameters for dysplasia were used to substratify the study population base: lateral center-edge angle (LCEA) ≤25° and LCEA >25°, acetabular inclination (AI) ≤10° and AI >10°, and anterior center-edge angle (ACEA) ≤20° and ACEA >20°. Results: For the LCEA ≤25° group, there were 28 hips with mean LCEA of 20.96° ± 3.40°. Patients with LCEA ≤25° had larger labral width in all 4 quadrants (P < .05). For AI >10°, there were 12 hips with the mean AI 12.92° ± 2.50°. Patients with AI >10° had larger labral size in the posteroinferior quadrant only (P < .05). For ACEA ≤20°, there were 4 hips with a mean ACEA of 11.25° ± 5.19°. The anteroinferior and posteroinferior quadrants had a significant increase in labral size when substratified by ACEA ≤20° (P < .05). Conclusion: Labral size was significantly larger in dysplastic hips compared with nondysplastic hips. The posteroinferior quadrant labrum was larger in size in dysplastic hips, as measured by any of the 3 radiographic measurements of dysplasia. Hips with LCEA ≤25° had larger labra in all 4 quadrants.

Labral Injury: Radiographic Predictors at the Time of Hip Arthroscopy

PURPOSE The purpose of this study was to investigate the influence of multiple demographic and radiographic findings on the size of labral tears identified at the time of hip arthroscopy. METHODS Data were prospectively collected for patients treated with arthroscopic labral repair or debridement from February 2008 to August 2011. Preoperative radiographic and demographic data were collected for 392 patients during the study period. Exclusion criteria included revision surgery and previous hip conditions. An anteroposterior pelvic view, 45° Dunn view, and false-profile view were used to measure Tönnis grade, neck-shaft angle, alpha angle, lateral center edge angle (LCEA), anterior center edge angle (ACEA), acetabular inclination, and the extent of crossover sign when present. At the time of surgery, labral tear size and location were documented for all patients, using traditional acetabular clock face nomenclature for sizing. A multiple linear regression analysis was then performed to assess the correlation of radiographic and demographic findings with the size of the labral tear. RESULTS Regression analysis displayed statistical significance for sex (P < .0001), age (P < .0001), and alpha angle (P = .005) with labral tear size. For female patients, Tönnis grade (P = .0004) and neck-shaft angle (P = .004) correlated with labral tear size. This model accounted for only 26% of variation in labral tear size. CONCLUSIONS Preoperative risk factors for the extent of labral tear size are male sex, increasing age, and increasing alpha angle. Labral tears were larger in female patients with higher Tönnis grades and lower neck-shaft angles. Measurements of acetabular coverage and version showed no correlation with labral tear size. The majority of labral tear size variation was not accounted for in this model. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Arthroscopic Decompression of Central Acetabular Impingement With Notchplasty

Acetabular notch osteophytes are often encountered during routine diagnostic arthroscopy of the hip. It has been our observation that when notch osteophytes are present, there is often corresponding chondral damage to the anterosuperior femoral head and ligamentum teres degeneration. We propose that removal of the notch osteophyte and decompression of the articulating surface offer an effective method of delaying the progression of arthritis. This article describes in detail the technique used to perform arthroscopic acetabular notchplasty, and a companion video, demonstrating the procedure, is included. Our experience suggests that decompression of the acetabular notch can remove offending structural abnormalities that can potentially cause further chondral damage and may hasten the progression of arthritis.

Arthroscopic ligamentum teres reconstruction of the hip in Ehlers-Danlos syndrome: a case study.

Background Ehlers-Danlos syndrome (EDS) is a genetic disorder that affects the structural integrity of collagen within the body. This presents clinically as a connective tissue disorder with increased elasticity of joints, muscles, and ligaments. Multiple joints are affected by hypermobility and joint injury is common in these patients. It is estimated that EDS occurs once in every 5,000 births worldwide. Case review This article focuses on reconstruction of the ligamentum teres (LT) of the hip using a tibialis anterior allograft to treat severe instability and pain in a 43 year-old female with EDS. The LT reconstruction was accompanied by labral repair and capsular plication. The patient was assessed pre- and postoperatively using modified Harris Hip Score (mHHS), Hip Outcome Score Activities of Daily Living (HOS-ADLS), Hip Outcome Score Sports Specific Subscale (HOS-SSS), Non Arthritic Hip Score (NAHS), Visual Analog Scale (VAS), and satisfaction. One year following surgery the patient has reported positive outcomes in terms of pain and instability. Literature review Ligament reconstruction has been reported in patients with Ehlers-Danlos syndrome for shoulders and knees with positive results and restoration of stability. Currently there is a paucity of literature regarding patients with EDS undergoing hip procedures. In addition, reconstruction of the ligamentum teres for hip instability and pain has rarely been reported in a normal patient cohort. Clinical relevance This is the first study to report ligamentum teres reconstruction of the hip in a patient with Ehlers-Danlos syndrome and hip instability. The patient demonstrated satisfactory results 1 year from surgery.

Does Robotic-Assisted Computer Navigation Affect Acetabular Cup Positioning in Total Hip Arthroplasty in the Obese Patient? A Comparison Study.

Obese populations present challenges for acetabular cup placement during total hip arthroplasty (THA). This study examines the accuracy of acetabular cup inclination and version in the obese patient with robotic-assisted computer navigation. A total of 105 patients underwent robotic-assisted computer navigation THA with a posterior approach. Groups were divided on body mass index (BMI, kg/m(2)) of <30, 30-35, and >35. There was no statistical difference between the BMI <30 (n=59), BMI 30-35 (n=34) and BMI >35 (n=12) groups for acetabular inclination (P=0.43) or version (P=0.95). Robotic-assisted computer navigation provided accurate and reproducible placement of the acetabular cup within safe zones for inclination and version in the obese patient.