Anterior capsulectomy versus repair in direct anterior total hip arthroplasty.

BACKGROUND: Utilization of the direct anterior approach for total hip arthroplasty (DAA THA) has increased over the last ten years. The preservation and repair of the anterior hip capsule has been recommended, while anterior capsulectomy has been described by others. In contrast, the higher risk of posterior dislocation using the posterior approach improved significantly after capsular repair. No studies to date have investigated outcome scores based on capsular repair versus capsulectomy for the DAA. METHODS: Patients randomized to anterior capsulectomy or anterior capsule repair. Patients were blinded to their randomization. Maximum hip flexion was measured both radiographically and clinically with a goniometer. Using a one-sided t test assuming equal variance with an effect size, Cohen's d, of 0.6 and an alpha of 0.05, 36 patients in each group (total 72 patients) needed for a minimum 80% power. RESULTS: Median goniometer measurements preoperatively were 95° for repair (IQR 85-100) and 91° for capsulectomy (IQR 82-97.5) (p = 0.52). Four-month and one-year goniometer measurements also had no significant difference, 110° (IQR 105-120) and 110° (IQR 105-120) for repair and 105° (IQR 96-116) and 109° (IQR 102-120) for capsulectomy (p = 0.38 and p = 0.26). Median change in flexion as measured by goniometer at 4 months and one year was 12 and 9 degrees for repair and 9.5 and 3 degrees for capsulectomy (p = 0.53 and p = 0.46). X-ray analysis showed no differences in pre-op, 4-month, and one-year flexion with median one-year flexion of 105.5° (IQR 96-109.5) for repair and 100° (IQR 93.5-112) for capsulectomy (p = 0.35). VAS scores were the same for both groups at all three time points. HOOS scores improved equally for both groups. There are no differences in surgeon randomization, age, or gender. CONCLUSIONS: Both capsular repair and capsulectomy used in direct anterior approach THA result in equal maximum clinical as well as radiographic hip flexion with no change in postoperative pain or HOOS scores.

Total Hip Arthroplasty in Patients With Severe Chronic Pubic Diastasis.

Background: Total hip arthroplasty (THA) in patients with severe chronic pubic diastasis from either congenital or acquired causes presents an exceptionally difficult challenge that has rarely been addressed in the arthroplasty literature. The purpose of this paper is to present a series of THAs in patients with severe chronic pubic diastasis, asking the following research questions: (1) What is the survivorship and clinical outcomes after THA in patients with severe chronic pubic diastasis? And (2) What is the rate of complications after THA surgery in this challenging patient population? We additionally describe our algorithm for preoperative planning and rationale for surgical technique and implant position. Material and methods: We retrospectively queried the prospective arthroplasty database of 2 high-volume referral centers, yielding 6 THA in 4 patients with severe chronic pubic diastasis (minimum 8 cm) with a mean follow-up of 2.7 years. We recorded baseline demographic and intraoperative variables, as well as survivorship, patient-reported outcomes (Hip disability and Osteoarthritis Outcome Score for Joint Replacement score), and incidence of complications. Results: There were no failures reported (100% survivorship) at a mean follow-up of 2.7 years. Mean Hip disability and Osteoarthritis Outcome Score for Joint Replacement scores improved from 36.0 preoperatively to 82.8 postoperatively. There were no infections, dislocations, fractures, or any major complications in the postoperative period. Conclusion: THA for patients with severe chronic pubic diastasis remains a rare but challenging reconstructive procedure. Excellent outcomes can be achieved with adequate preparation, particularly regarding the acetabular component position. Understanding the nature of the hemipelvis deformity and meticulous templating using "normalized" views of the hip are important components to a successful preoperative plan.

Results of the First U.S. FDA-Approved Hip Resurfacing Device at 10-Year Follow-up.

BACKGROUND: The BIRMINGHAM HIP Resurfacing (BHR) system is a metal-on-metal hip implant system approved by the U.S. Food and Drug Administration in 2006. The approval required a multicenter, prospective, post-market-approval study. Our purpose is to report the current results at 10 years of follow-up. METHODS: Between October 2006 and December 2009, 280 primary BHR procedures were performed at 5 sites. Outcome measures included Kaplan-Meier survivorship, reasons for revision, radiographic component stability and osteolysis, Harris hip scores, and metal levels including cobalt and chromium. The mean age at the time of the procedure was 51.3 ± 7.1 years, 74% (206) of 280 BHRs were implanted in male patients, the mean body mass index was 27.8 ± 4.4 kg/m2, and 95% (265) of 280 hips had a primary diagnosis of osteoarthritis. The mean follow-up among all 280 hips was 9.0 ± 2.5 years. Prior to 10-year follow-up, 20 hips were revised and 5 patients representing 5 hips had died. Among the remaining 255 hips, 218 (85%) met the minimum follow-up of 10 years. RESULTS: The 10-year survival free from all-cause component revision was 92.9% (95% confidence interval [CI], 89.8% to 96.1%) for all hips and 96.0% (95% CI, 93.1% to 98.9%) among male patients <65 years old at the time of the procedure. Reasons for revision included femoral loosening (n = 5), femoral neck fracture (n = 3), pseudotumor (n = 3), osteolysis (n = 2), and acetabular loosening (n = 1), as well as 6 revisions for a combination of pain, noise, or metal levels. Among unrevised hips, the median Harris hip score improved from preoperatively (59) to 1 year postoperatively (99; p < 0.001) and remained stable through 10 years postoperatively (99; p = 0.08). Radiographically, 5% (10) of 218 unrevised hips had osteolysis with no component migration. Median metal levels had increased at 1 year postoperatively (cobalt: from 0.12 ppb preoperatively to 1.5 ppb at 1 year postoperatively, p < 0.001; chromium: from 0.6 ppb preoperatively to 1.7 ppb at 1 year postoperatively, p < 0.001), then remained stable through 5 years before slightly decreasing at 10 years postoperatively (cobalt: 1.3 ppb, p < 0.001; chromium: 1.4 ppb, p < 0.001). CONCLUSIONS: This prospective, multicenter, post-market-approval study demonstrated that the BHR implant system is safe and effective through 10 years of follow-up, particularly among young male patients. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Acetabular Exposure Is Enhanced With Self-Retaining Retractors During Direct Anterior Total Hip Arthroplasty.

Acetabular exposure for direct anterior (DA) total hip arthroplasty (THA) can be performed using hands-free, self-retaining retractors. No current study quantitatively compares this self-retaining technique with the traditional manual technique. In 65 consecutive DA THA hips, two "best-view" digital photographs were taken of the exposure-one using Charnley/self-retaining retractors and one using a traditional three-retractor manual technique. Percent exposure of the polyethylene liner was calculated. Percent acetabular exposure averaged 80.0% using the Charnley/self-retaining technique, compared with 73.1% using the manual technique (P=.0002). A hands-free technique provides superior acetabular exposure compared with the manual technique. Increasing body mass index predicts decreasing exposure with both techniques. [Orthopedics. 2021;44(2):e309-e313.].

The Direct Anterior Approach Total Hip Arthroplasty Reliably Achieves "Safe Zones" for Combined Anteversion.

BACKGROUND: In total hip arthroplasty (THA), component position is critical to avoid instability and improve longevity. Appropriate combined femoral and acetabular component anteversion is important for improved THA stability and increased impingement-free range of motion. In direct anterior THA (DA-THA), concern has been expressed regarding the accuracy of femoral component positioning. This study seeks to quantify acetabular, femoral, and combined component orientation relative to the accepted "safe zones" in patients who have undergone DA-THA. METHODS: Twenty-nine patients who had THA performed via direct anterior approach had postoperative computerized tomography scans done to assess femoral anteversion. Stem rotational alignment was measured relative to the transepicondylar axis (TEA) and the posterior condylar axis (PCA) of the femur at the knee. Acetabular abduction and version were recorded on anteroposterior pelvis radiographs. RESULTS: The mean stem anteversion was 17.5° (standard deviation = 10.8°) from the TEA and 21.7° (standard deviation = 11.3°) from the PCA. Ten of 30 cups were appropriately anteverted; however, all the cups had appropriate abduction. Combined version when using the TEA resulted in 79% (23/29) of patients within the "safe zone" of 25°-50°. Pearson correlation coefficients were high for both stem anteversion from the TEA (R = 0.96) and PCA (R = 0.98); however, interobserver reliability for combined component anteversion was greater for the TEA (kappa, 0.83 vs 0.65). CONCLUSIONS: Combined anteversion within the "safe zone" was achieved 79% of the time with DA-THA. Interestingly, most of the "excessive" combined anteversion appears to be related to increased anteversion of the acetabular component with only 10 patients within the acetabular cup "safe zone" of 5°-25°.

Anatomic Total Hip Component Position Is More Reproducible With the Direct Anterior Approach Using Intraoperative Fluoroscopy.

BACKGROUND: Total hip arthroplasty (THA) has demonstrated excellent results regardless of the surgical approach. However, the approach used may be a factor in final positioning of implants. We hypothesized that the direct anterior approach (DAA) with fluoroscopy would be associated with more anatomic implant positioning than the posterior approach (PA). METHODS: A retrospective review of 200 patients was performed. One hundred patients underwent THA utilizing the PA, and 100 patients, with the DAA. All patients had an anterior-posterior pelvis radiograph preoperatively and postoperatively with a magnification marker present to standardize each radiograph. Exclusion criteria included contralateral THA or any pelvic or femoral deformity. RESULTS: Preoperative radiographs demonstrated identical cohorts with respect to leg length, femoral offset, and total offset. Postoperatively, the DAA achieved more accurate anatomic restoration of leg length (1.6 mm vs 5.5 mm; P < .0001), femoral offset (4.8 mm vs 9.3 mm; P < .0001), and total offset (0.5 mm vs 4.7 mm; P < .0001) compared with the PA. Ideal cup abduction and anteversion were significantly superior to the DAA (96% vs 78%, P = .0002, and 69% vs 24%, P < .0001, respectively). CONCLUSIONS: This study is the first to compare anatomic implant positioning between patients undergoing THA with these 2 approaches. All parameters were significantly closer to anatomic implant positioning with the DAA. There are at least 2 potential explanations for this: (1) The DAA implant positioning was performed under fluoroscopic guidance, whereas the PA was not. (2) The PA disrupts the posterior capsule and external rotators, and therefore, increased offset or leg length may be necessary to achieve comparable hip stability with the DAA.

Extensile Femoral Exposure/Femoral Revision Techniques Via the Direct Anterior Approach.

The goal of this chapter is to describe the extensile femoral exposure options and femoral revision techniques using the direct anterior approach (DAA) in total hip arthroplasty. Although DAA is initially described as a muscle-sparing exposure for primary hip arthroplasty, because of its internervous anatomic dissection, the internervous and intermuscular benefits of the DAA are maintained throughout the revision exposure. This distinguishing feature of the DAA must be respected to promote maximal muscle function and stability following revision surgery. Femoral revision exposure can be challenging through any surgical approach. The direct anterior exposure provides a unique access angle to the femur and therefore the incision, releases, osteotomies, and stem insertion techniques differ in many respects from more traditional exposures. The authors hope that this chapter will expose surgeons to the cascade of revision anterior femoral exposure and demonstrate the key elements for successful revision surgery.

Acetabular Revision via Direct Anterior Approach-Technical Considerations.

Acetabular implant revision is commonly performed during revision total hip arthroplasty (THA).1 With recent significant increase in the utilization of direct anterior approach for primary THA,2,3 many surgeons familiar with this approach are exploring the direct anterior for revision THA (r-THA) applications. This chapter will specifically address acetabular implant revision via direct anterior approach. The exposure techniques for the acetabulum are described elsewhere in this lecture series. Instead, attention to the mechanics and techniques of acetabular implant revision via direct anterior approach will be stressed.

Dual Mobility for Monoblock Metal-on-Metal Revision-Is It Safe?

BACKGROUND: Revision of monoblock metal-on-metal (MoM) total hip arthroplasty (THA) is associated with high complication rates. Limited revision by conversion to a dual mobility (DM) without acetabular component extraction may mitigate these complications. However, the concern for polyethylene wear and osteolysis remains unsettled. This study investigates the results of DM conversion of monoblock MoM THA compared to formal acetabular revision. METHODS: One hundred forty-three revisions of monoblock MoM THA were reviewed. Twenty-nine were revisions to a DM construct, and 114 were complete revisions of the acetabular component. Mean patient age was 61, 54% were women. Components used, acetabular cup position, radiographic outcomes, serum metal ion levels, and HOOS Jr clinical outcome scores were investigated. RESULTS: At 3.9 years of follow-up (range 2-5), there were 2 revisions (6.9%) in the DM cohort, 1 for instability and another for periprosthetic fracture. Among the formal acetabular revision group there was a 20% major complication rate (23/114) and 16% underwent revision surgery (18/114) for aseptic loosening of the acetabular component (6%), deep infection (6%), dislocation (4%), acetabular fracture (3%), or delayed wound healing (6%). In the DM cohort, there were no radiographic signs of aseptic loosening, component migration, or polyethylene wear. One DM patient had a small posterior metadiaphyseal femur lesion that will require close monitoring. There were no other radiographic signs of osteolysis. There were no clinically significant elevations of serum metal ion levels. HOOS Jr scores were favorable. CONCLUSION: Limited revision with conversion to DM is a viable treatment option for failed monoblock MoM THA with lower complication rates than formal revision. Limited revision to DM appears to be a safe option for revision of monoblock MoM THA with a cup in good position and an internal geometry free of sharp edges or articular surface damage. Longer follow-up is needed to demonstrate any potential wear implications of these articulations.

Repair of the Released Conjoined Tendon After Direct Anterior Total Hip Arthroplasty.

Release of the conjoined tendon has been reported to facilitate femoral exposure during a direct anterior hip approach. However, the authors are not familiar with any description of an anterior approach repair technique for this important structure. Conjoined tendon repair is commonly performed in the posterior approach to help preserve hip biomechanics and restore anatomic tissue planes. The authors describe their algorithm for sequential soft tissue releases to facilitate femoral exposure and a technique for repairing the insertion of the conjoined tendon after it has been released for exposure during the direct anterior approach. [Orthopedics. 2018; 41(4):e583-e586.].

Early Failure of Primary Total Hip Arthroplasty: Is Surgical Approach a Risk Factor?

BACKGROUND: In an era of innovation in surgical approaches for total hip arthroplasty (THA), there is concern for increasing trends of early failure. The purpose of this study is to evaluate the incidence of early failure of primary THA stratified by surgical approach. METHODS: A retrospective review was performed on consecutive primary THAs completed from 2007 to 2014 at a high-volume center. THAs were stratified by surgical approach. Only the direct anterior (DAA) and posterior approaches (PA) were included. The primary outcome measure was early revision (<5 years). Descriptive statistics were performed using SAS software. RESULTS: In total, 6894 primary THAs performed between 2007 and 2014 were included. Across 2431 DAA THAs and 4463 PA THAs, there were 103 revisions overall. There was no difference in the overall revision rate for DAA THAs (1.69%) compared to PA THAs (1.39%) (P = .33). The DAA had a higher rate of early revisions for femoral component loosening compared to the PA (P = .0003). About 35.7% of DAA THAs were revised for femoral loosening compared to 8% for the PA (P = .0003). Early failure by femoral loosening occurred more often via the DAA in Dorr A bone (P = .03). The PA had a higher incidence of revision for instability (P = .04). There was no difference in modes of failure with regards to time to failure, acetabular loosening, early periprosthetic fracture, or infection. CONCLUSION: The DAA had a higher incidence of femoral loosening while PA had a higher mode of failure due to instability. Overall revision rates were not statistically different between approaches.

Radiation Exposure During Fluoro-Assisted Direct Anterior Total Hip Arthroplasty.

BACKGROUND: Utilization of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in the last decade with fluoroscopy often used to confirm implant position, leg length, and offset. Radiation exposure thresholds around 800 mGy are published for the risk of cataracts. We hypothesized that surgeon eye exposure during fluoro-assisted DAA total hip arthroplasty would be well below these published thresholds. METHODS: Three experienced orthopedic surgeons performed 30 consecutive fluoro-assisted DAA THAs. During each procedure, the surgeon wore a helmet-mounted dosimeter. After 30 consecutive cases, the dosimeters were analyzed. A chart review was then completed to obtain fluoroscopic data saved for each individual case including fluoroscopic time, total radiation dose, and radiation tech experience. RESULTS: Fluoroscopic data were available for 89 of 90 cases (98.8%). Surgeon 1 had an average fluoroscopic time of 18.51 seconds, radiation dose of 2.396 mGy, and tech experience of 13.06 years. Surgeon 2 had an average fluoroscopic time of 15.63 seconds, radiation dose of 2.139 mGy, and tech experience of 23.69 years. Surgeon 3 had an average fluoroscopic time of 11.06 seconds, radiation dose of 1.462 mGy, and tech experience of 16.03 years. The dosimeter results were 8, 5, and <1 mrem, respectively, for each surgeon. The mean total radiation dose per case for all surgeons was 2.00 mGy (±1.31), and there was no correlation between radiation dose and radiologic tech experience (0.089, P > .05) or radiation dose and patients' body mass index (0.260, P = .014). CONCLUSIONS: Each surgeon would need to perform >300,000 DAA THAs to exceed the 800-mGy cataract threshold dose. The decision to wear protective glasses should be at the surgeon's discretion; however, the findings in this study show a very low radiation dose to the surgeon's eye regardless of radiologic tech experience or patient's body mass index.

Five year results of the first US FDA-approved hip resurfacing device.

A prospective, multi-center postmarket approval study has been ongoing since May 2006 to assess safety and efficacy of the first US FDA approved hip resurfacing implant. 265 patients have been enrolled at five study sites. The average age of the patients is 51.3 years. There have been 7 revisions (2.4%) in the cohort to date. K-M survival curves for the cohort are 97.6% at 5 years. There is a trend toward a gender difference in implant survivorship, with 98.6% of men and 94.7% of women free from revision. Metal ion analysis revealed median cobalt and chromium levels of 1.5 ppb and 1.7 ppb at 1 year. In this prospective US study, the Birmingham Hip Resurfacing implant is demonstrating results comparable to those in the literature.

Comparative analysis of periarticular osteolysis in modern total hip bearings: a minimum 5-year study.

The best bearing to use in the young active population remains unknown because there are currently no evidence-based data to rely on. This article compares the prevalence of periacetabular osteolysis using computerized tomography in patients with metal-on-metal, ceramic-on-ceramic, and metal-on-cross-linked bearings at a minimum 5-year follow-up.

Early failures in unicondylar arthroplasty.

Unicondylar arthroplasty has reemerged as an option for isolated compartment knee arthritis. We have noticed an increase in the need for early revision of this construct at our revision center. This study sought to determine if the need for unicondylar revision has increased over time and what factors may have led to early failure. Revision total knee arthroplasties (TKAs) performed between 1990 and 1999 (period 1) were compared to TKAs performed between 2000 and 2008 (period 2). The prevalence of unicondylar revision, time to failure, and reasons for failure were calculated. Between 1990 and 1999, 425 revision TKAs were performed, 7 of which were uni-revisions (1.6%). These had been in place an average of 169 months (range, 12.9-478.6 months). Between 2000 and 2008, 744 revision TKAs were performed, 43 of which were uni-revisions (5.8%). These had been in place an average of only 36 months (range, 4.2-159.5 months). The dominant reasons for failure in period 1 included poly wear and loosening. Reasons for failure in period 2 were variable but included a number of technical errors. Early failure of unicondylar arthroplasty appears to be on the rise. Acknowledging that these patients came from an unknown pool, we are concerned that market pressure may have led to inappropriate patient selection and that surgical inexperience with this procedure may have led to the technical problems noted in period 2. Patients should be apprised of the possibility of early revision with this procedure.

Comparison of autograft vs allograft in opening-wedge high tibial osteotomy.

Opening-wedge high tibial osteotomy (HTO) is used to treat isolated medial knee joint arthritis. A benefit of using allograft instead of autograft is avoiding a second surgical site, thereby decreasing operative time, blood loss, and pain. Our study objective was to evaluate allograft vs autograft in the failure and complication rates of HTO using the same technique and implant system (Arthrex HTO plate system, Arthrex, Inc, Naples, Fla). Seventy knees in 65 patients were evaluated. There was a 6-fold higher failure rate for the allograft group. When there was no lateral cortical breach, construct failure did not occur in 87.8% of the knees (P = .0006); with lateral cortical breach, construct failure occurred 53% of the time (P = .0006). Seventy-six and a half percent of breached cortices and 75% of failures were associated with large wedge sizes (>or=11 mm); this may suggest a role for closing-wedge osteotomy or alternative osteotomies when larger alignment corrections are needed.

Cementless femoral components in young patients: review and meta-analysis of total hip arthroplasty and hip resurfacing.

The study purpose was to analyze current results of modern cementless femoral components in young patients having total hip arthroplasty (THA) or hip resurfacing. Twenty-two studies (n = 5907; hips = 6408) evaluating modern cementless THA in young patients and 15 studies evaluating hip resurfacing (n = 3002; hips = 3269) were included. Meta-analysis techniques were used to pool failure rates. The pooled failure rate for THA using femoral revision for mechanical failure as an end point was 1.3% (95% confidence interval [CI], 1.0%-1.7%) at a mean 8.4 years of follow-up. At a mean of 3.9 years of follow-up, the pooled mechanical failure rate of the femoral component for hip resurfacing was 2.6% (95% CI, 2.0-3.4). In conclusion, the enthusiasm for hip resurfacing should be tempered by these data. Longer follow-up and direct comparison trials are required to confirm these findings.

Why revision total hip arthroplasty fails.

UNLABELLED: Current outcomes data on revision total hip arthroplasty focuses on specific implants and techniques rather than more general outcomes. We therefore examined a large consecutive series of failed THAs undergoing revision to determine if survivorship and modes of failure differ in comparison to the current data. We retrospectively reviewed the medical records of 1100 revision THAs. The minimum followup was 2 years (mean, 6 years; range, 0-20.4 years). Eighty-seven percent of revision total hips required no further surgery; however, 141 hips (13%) underwent a second revision at a mean of 3.7 years (range, 0.025-15.9 years). Seventy percent (98 hips) had a second revision for a diagnosis different from that of their index revision, while 30% (43 hips) had a second revision for the same diagnosis. The most common reasons for failure were instability (49 of 141 hips, 35%), aseptic loosening (42 of 141 hips, 30%), osteolysis and/or wear (17 of 141 hips, 12%), infection (17 of 141 hips, 12%), miscellaneous (13 of 141 hips, 9%), and periprosthetic fracture (three of 141 hips, 2%). Survivorship for revision total hip arthroplasty using second revision as endpoint was 82% at 10 years. Aseptic loosening and instability accounted for 65% of these failures. LEVEL OF EVIDENCE: Level IV, therapeutic (retrospective) study. See the Guidelines for Authors for a complete description of levels of evidence.

Locked plating of supracondylar periprosthetic femur fractures.

Fifty periprosthetic supracondylar femur fractures above a total knee arthroplasty were reviewed. Fractures were closed Lewis and Rorabeck type II with a stable prosthesis. Twenty-nine patients (group I), were treated with locked condylar plating. Twenty-one patients (group II) were treated with nonlocked plating systems or intramedullary fixation. Minimum follow-up was 1.7 years. There were 5 malunions (20%) in group I and 9 (47%) in group II (P < .05). There were no nonunions in group I and 3 (16%) in group II. Complication rates were 12% in group I, compared to 42% in group II. Group I patients had less operative blood loss, healed in better alignment, and had greater knee motion. All 7 patients treated with a retrograde intramedullary nail developed a malunion or nonunion. Locked plating is a reliable treatment for periprosthetic supracondylar femur fractures. We experienced a lower complication, revision, malunion, and nonunion rate with locked plating versus conventional treatment options.

Patient out-of-pocket expenses in major orthopedic procedures: total hip arthroplasty as a case study.

Total hip arthroplasty (THA) is a successful procedure for improving quality of life. There are few publications regarding out-of-pocket expenses incurred by individuals undergoing uncomplicated THA. Detailed billing and record reviews and patient phone surveys were conducted on 34 Medicare patients identifying charges and reimbursements recorded by the health care system and all out-of-pocket expenses incurred by patients undergoing uncomplicated THA (diagnostic related group [DRG] 209/current procedural terminology [CPT] 27130). Mean THA total billed charges were $46378, 89% of that from inpatient hospitalization and 5% incurred preoperatively and 7% postoperatively. Medicare reimbursement was $14647, supplemental reimbursement was $744, and patients paid a mean out-of-pocket expense of $758 (95% CI, 614-904; range, 102-1889). Our study supports the policy that THA remains an excellent value to both the patient and society.