Faculty Bibliography

Periacetabular osteotomy (PAO) is an effective surgical treatment for hip dysplasia. The goal of PAO is to reorient the acetabulum to improve joint stability, lessen contact stresses and slow the development of hip arthrosis. During PAO, the acetabulum is repositioned to adequately cover the femoral head. PAO preserves the weight-bearing posterior column of the pelvis, maintains the acetabular blood supply and retains the hip abductor musculature. The surgical technique needed to perform PAO is technically demanding, with correct repositioning of the acetabulum the most important-and challenging-aspect of the procedure. Imageless navigation has proven useful in other technically challenging surgeries, although its use in PAO has not yet been investigated. We have modified the standard technique for PAO to include the use of an imageless navigation system to confirm acetabular fragment position following osteotomy. Here, we describe the surgical technique and discuss the potential of this modified technique to improve patient-related outcomes.

BACKGROUND:Total hip arthroplasty (THA) is a frequently performed, highly successful orthopedic procedure. Although primary osteoarthritis (PA) is the most common reason for (THA), there are several secondary conditions that lead to degenerative hip disease that are successfully treated with THA. The purpose of this study was to examine the incidence of these secondary causes of arthritis (SA) leading to THA and to compare the relative surgical costs, operating times, and hospital length of stay (LOS) for THA done for PA versus SA. METHODS:Electronic medical records from 836 continuous patients undergoing primary THA over a 2-year period were reviewed at a single high-volume joint arthroplasty center. Data obtained included age, sex, laterality, diagnosis leading to THA, surgical costs based on hospital fees, operating room time, and hospital LOS. Using operative reports, office visit notes, and radiology reports or images, patients were categorized into PA or SA groupings. PA was defined as osteoarthritis of no other known etiology, whereas SA was defined when a known underlying diagnosis led to degenerative joint disease of the hip. SA included hip dysplasia, post-traumatic arthritis (PTA), avascular necrosis (AVN), inflammatory arthropathy, Perthes disease, and slipped capital femoral epiphysis (SCFE). Means and proportions of the variables from both groups were analyzed and compared using t-tests and chi-squared tests where applicable. RESULTS:There were 599 patients in the PA group and 237 patients in the SA group. The SA group was significantly younger than the PA group (54.4 years versus 64.0 years; p = 0.0001). The SA cohort had significantly higher mean surgical costs ($29,662 versus $27,078; p = 0.0005), operating room times (189 minutes versus 179 minutes; p = 0.0042), and LOS (4.2 days versus 3.9 days; p = 0.0312). Within the SA group, the hip dysplasia subgrouping had the lowest cost and operating room time, whereas the PTA subgrouping had the highest cost and operating room time. CONCLUSIONS:More than a quarter of primary THAs are performed due to secondary arthritis, most commonly due to hip dysplasia. Cases of THA due to secondary arthritis are associated with significantly increased hospital costs, operating time, and postoperative length of stay compared to THA's performed for primary osteoarthritis. Patients with post-traumatic hip arthritis may contribute the highest economic burden and present the most complex cases for arthroplasty surgeons.

Purpose/UNASSIGNED:The optimal treatment for late-presenting developmental dysplasia of the hip (DDH) is controversial. High tension forces after hip reduction increase the pressure on the femoral head, potentially causing avascular necrosis. Femoral shortening (FS) is commonly used as a means to decrease the pressure on the femoral head. We examined the effect of FS on the outcomes of patients with late-presenting DDH. Methods/UNASSIGNED:A total of 645 hips of a late-presenting DDH cohort treated with open reduction and iliac osteotomies were retrospectively reviewed; 328 hips had a FS performed (FS+) and 317 (FS-) had not. The mean age was 3.9 years (sd 1.55). We classified the hips with the Tönnis and International Hip Dysplasia Institute (IHDI) methods; and the Pediatric Outcomes Data Collection Instrument (PODCI), Iowa Hip Score (IHS) and Severin classification as outcome measurements. Results/UNASSIGNED:The FS- group had higher scores in PODCI (median 95 points; interquartile range (IQR) 78 to 91) and IHS (median 91 points; IQR 64 to 88) than the FS+ group (PODCI: median 94 points; IQR 69 to 89 points; IHS: median 89 points; IQR 62 to 87). The mean Severin scores were similar (FS- 2.65; FS+ 2.5; p = 0.93) but the FS- group had higher rates of good and excellent outcomes (FS- 56%; FS+ 41%; p < 0.00001) and lesser dislocation rates (FS- 6%; FS+ 14%; p = 0.16). Conclusion/UNASSIGNED:Although FS should be used when a hip cannot be reduced without undue tension, our results indicate that this procedure is not necessarily related to a better outcome. Level of evidence/UNASSIGNED:Therapeutic, Level III.

Purpose/UNASSIGNED:Patients with late-presenting developmental dysplasia of the hip (DDH) are more likely to require an open reduction. Since many developing countries do not have mandated screening, there continues to be a relatively high incidence of late-presenting DDH. We report the clinical and radiographic outcomes of open reduction in a series of patients who presented late. Patients and methods/UNASSIGNED:This was a retrospective review of 712 hips in 645 patients that underwent open reduction, alone or in combination with a pelvic osteotomy. In all, 91 hips had open reduction alone and 621 had open reduction and pelvic osteotomy. Femoral shortening was performed in 221 hips. The mean age at the time of surgery was 2.1 years (1 to 6.5) and the mean follow-up time was 9.3 years (6 to 14). We used the Children's Hospital Oakland Hip Evaluation Score (CHOHES) to determine functional outcomes and the Severin classification was used to evaluate radiographic outcomes. The rate of avascular necrosis (AVN) and the need for a reoperation were also recorded and analyzed. Results/UNASSIGNED:In all 80% (570 hips) had good radiographic outcomes (Severin type I or II) and 87% had a CHOHES score of > 90 at final follow up. There was a 14% rate of AVN and only a 2% rate of redislocation. Better radiographic outcomes and lower reoperation rates were seen with patients who underwent both an open reduction and pelvic osteotomy. A trend was observed towards worse outcomes in older patients. Conclusions/UNASSIGNED:There was a high rate of good clinical and radiographic outcomes at a minimum six-year follow-up in patients with late-presenting DDH who underwent open reduction. Those who underwent open reduction in combination with a pelvic osteotomy had a higher rate of good radiographic outcomes and a lower rate of complications, particularly reoperation.

BACKGROUND: Femoroacetabular impingement is increasingly recognized as a cause of hip pain but its incidence after an innominate osteotomy for the correction of acetabular dysplasia has not been determined. This information would be essential for the orthopaedic surgeon because it has the potential to produce a poor outcome in the long term when trying to balance acetabular instability and overcorrection. QUESTIONS/PURPOSES: The purposes of our study were (1) to determine the frequency with which clinically relevant femoroacetabular impingement (FAI) occurs after an innominate osteotomy for the treatment of acetabular dysplasia; (2) to determine risk factors for the development of FAI; and (3) to compare postoperative radiographic and clinical outcomes in patients having undergone an innominate osteotomy for the correction of acetabular dysplasia both with and without FAI. METHODS: This was a retrospective review of 154 hips (132 patients) that had undergone an innominate osteotomy for acetabular dysplasia and were evaluated at a minimum followup of 10 years (mean = 12 years). Mean age at the time of surgery was 3 years, 114 hips had a concomitant open reduction, and 54 hips also had femoral shortening. One hundred eight hips had a Salter osteotomy and 46 had a Pemberton osteotomy. Radiographs were analyzed to determine the lateral center-edge angle (CE angle) and the presence of a crossover sign. The diagnosis of FAI was established when the CE angle was greater than 40 degrees , there was a positive crossover sign, and the patient had groin pain when flexing the hip less than 90 degrees . Comparisons between nonparametric variables were performed with a Mann-Whitney's U test. Categorical variables were compared with a chi-square test. Change in acetabular index (correction) was dichotomized considering 20 degrees of correction as the cutoff point. Association is presented as odds ratio (95% confidence interval), and logistic regression was performed. RESULTS: According to our criteria, 18 of 154 hips had FAI (12%). Of the 18 patients with FAI, 10 had undergone a Pemberton osteotomy (10 of 46 [22%]) and eight a Salter osteotomy (eight of 108 [7%]). A change in the postoperative acetabular index greater than 20 degrees was associated with a greater likelihood of developing FAI. The mean postoperative acetabular index was lower for the group with FAI, for whom it was 20 degrees , compared with the group without FAI, for whom it was 27 degrees (p = 0.04). The mean Iowa Hip Score for the group with FAI was 85, whereas for those without FAI, it was 93 (p = 0.03). CONCLUSIONS: FAI is not common after an innominate osteotomy for the treatment of acetabular dysplasia; however, overcorrection is related to a higher incidence. When FAI is present, it can affect the outcome. Overcorrection should be avoided when performing an innominate osteotomy for the treatment of acetabular dysplasia because it can create iatrogenic FAI and have an adverse effect on outcome. LEVEL OF EVIDENCE: Level III, therapeutic study.

BACKGROUND: Little information exists concerning the variability of presentation and differences in treatment methods for developmental dysplasia of the hip (DDH) in children < 18 months. The inherent advantages of prospective multicenter studies are well documented, but data from different centers may differ in terms of important variables such as patient demographics, diagnoses, and treatment or management decisions. The purpose of this study was to determine whether there is a difference in baseline data among the nine centers in five countries affiliated with the International Hip Dysplasia Institute to establish the need to consider the center as a key variable in multicenter studies. QUESTIONS/PURPOSES: (1) How do patient demographics differ across participating centers at presentation? (2) How do patient diagnoses (severity and laterality) differ across centers? (3) How do initial treatment approaches differ across participating centers? METHODS: A multicenter prospective hip dysplasia study database was analyzed from 2010 to April 2015. Patients younger than 6 months of age at diagnosis were included if at least one hip was completely dislocated, whereas patients between 6 and 18 months of age at diagnosis were included with any form of DDH. Participating centers (academic, urban, tertiary care hospitals) span five countries across three continents. Baseline data (patient demographics, diagnosis, swaddling history, baseline International Hip Dysplasia Institute classification, and initial treatment) were compared among all nine centers. A total of 496 patients were enrolled with site enrolment ranging from 10 to 117. The proportion of eligible patients who were enrolled and followed at the nine participating centers was 98%. Patient enrollment rates were similar across all sites, and data collection/completeness for relevant variables at initial presentation was comparable. RESULTS: In total, 83% of all patients were female (410 of 496), and the median age at presentation was 2.2 months (range, 0-18 months). Breech presentation occurred more often in younger (< 6 months) than in older (6-18 months at diagnosis) patients (30% [96 of 318] versus 9% [15 of 161]; odds ratio [OR], 4.2; 95% confidence interval [CI], 2.3-7.5; p < 0.001). The Australia site was underrepresented in breech presentation in comparison to the other centers (8% [five of 66] versus 23% [111 of 479]; OR, 0.3, 95% CI, 0.1-0.7; p = 0.034). The largest diagnostic category was < 6 months, dislocated reducible (51% [253 of 496 patients]); however, the Australia and Boston sites had more irreducible dislocations compared with the other sites (ORs, 2.1 and 1.9; 95% CIs, 1.2-3.6 and 1.1-3.4; p = 0.02 and 0.015, respectively). Bilaterality was seen less often in older compared with younger patients (8% [seven of 93] versus 26% [85 of 328]; p < 0.001). The most common diagnostic group was Grade 3 (by International Hip Dysplasia Institute classification), which included 58% (51 of 88) of all classified dislocated hips. Splintage was the primary initial treatment of choice at 80% (395 of 496), but was far more likely in younger compared with older patients (94% [309 of 328] versus 18% [17 of 93]; p < 0.001). CONCLUSIONS: With the lack of strong prognostic indicators for DDH identified to date, the center is an important variable to include as a potential predictor of treatment success or failure.