Direct Anterior Approach for Primary Total Hip Arthroplasty Lowers the Risk of Dislocation Compared to the Posterior Approach: A Single Institution Experience.

BACKGROUND: One purported benefit of the direct anterior approach (DAA) for total hip arthroplasty (THA) is a lower rate of postoperative dislocation. METHODS: An institutional database was used to identify 8840 primary THAs performed from 2003 to 2020 including 5065 (57%) performed using the DAA and 3775 (43%) performed via the posterior approach (PA). Direction and mechanism of dislocation were determined from chart review. Outcomes were compared using Kaplan-Meier survivorship with dislocation as the endpoint and a Cox multivariate regression was used to investigate factors associated with dislocation. The mean follow-up was 1.7 ± 2.0 years for the DAA and 3.1 ± 3.3 years for the PA. RESULTS: The 0.5% (26/5065) incidence of dislocation among DAA hips was significantly less than the 3.3% (126/3775) among PA cases (P < .001). The majority of dislocations were posterior (DAA 57%, PA 79%) and occurred during activities of daily living (DAA 82%, PA 77%). Five-year survivorship was significantly higher for the DAA group compared to the PA group (99.1% vs 95.4%, P < .001). Dislocation risk was 4.9 times higher for the PA compared to the DAA (hazard ratio = 4.9, 95% confidence interval = 3.2-7.5, P < .001). Increasing head diameter reduced the risk (hazard ratio = 0.70, 95% confidence interval = 0.57-0.86, P < .001). The 0.2% incidence (10/5065) of revision for instability among the DAA group was significantly lower than the 1.1% (43/3775) rate for the PA group (P < .001). CONCLUSION: Compared to primary THAs performed with the PA, DAA cases had a lower risk of dislocation, higher survivorship with dislocation as an endpoint, and a lower risk of revision for instability in this single institution cohort.

Does Previous Hip Arthroscopy Affect the Clinical Outcomes of Total Hip Arthroplasty?

BACKGROUND: Failure of hip arthroscopy procedures and the need for subsequent total hip arthroplasty (THA) have been estimated to be as high as 16%. Prior literature has shown that failed ipsilateral knee arthroscopy may have a negative impact on the functional outcome of subsequent total knee arthroplasty. To date, there is limited information regarding the impact of failed hip arthroscopy on the clinical outcomes of subsequent primary THA. PURPOSE: To compare clinical outcomes in primary THA between patients with and without prior arthroscopic hip surgery. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients undergoing primary THA with a history of ipsilateral hip arthroscopy were matched and compared in a 1:2 manner with patients undergoing primary THA without a history of hip arthroscopy. Patient-reported clinical outcomes were measured with the modified Harris Hip Score, the University of California-Los Angeles Activity Score, and 3 subscales from the Western Ontario and McMaster Universities Osteoarthritis Index (Pain, Stiffness, and Physical Function). RESULTS: At a mean follow-up of 42 months, there was no significant difference in any of the outcome measures between the 58 study hips and 116 matched controls. Additionally, both groups exhibited an absolute change in outcome scores that exceeded the minimum clinically important difference. CONCLUSION: Prior ipsilateral arthroscopic hip surgery does not adversely affect the clinical outcome of subsequent THA.

The Arterial Anatomy of the Lateral Ligament Complex of the Ankle: A Cadaveric Study.

BACKGROUND: Ankle sprains are the most common musculoskeletal injury in the United States. Chronic lateral ankle instability can ultimately require operative intervention to decrease pain and restore stability to the ankle joint. There are no anatomic studies investigating the vascular supply to the lateral ankle ligamentous complex. PURPOSE: To define the vascular anatomy of the lateral ligament complex of the ankle. STUDY DESIGN: Descriptive laboratory study. METHODS: Thirty pairs of cadaveric specimens (60 total legs) were amputated below the knee. India ink, followed by Ward blue latex, was injected into the peroneal, anterior tibial, and posterior tibial arteries to identify the vascular supply of the lateral ligaments of the ankle. Chemical debridement was performed with 8.0% sodium hypochlorite to remove the soft tissues, leaving casts of the vascular anatomy intact. The vascular supply to the lateral ligament complex was then evaluated and recorded. RESULTS: The vascular supply to the lateral ankle ligaments was characterized in 56 specimens: 52 (92.9%) had arterial supply with an origin from the perforating anterior branch of the peroneal artery; 51 (91.1%), from the posterior branch of the peroneal artery; 29 (51.8%), from the lateral tarsal branch of the dorsalis pedis; and 12 (21.4%), from the posterior tibial artery. The anterior branch of the peroneal artery was the dominant vascular supply in 39 specimens (69.6%). CONCLUSION: There are 4 separate sources of extraosseous blood supply to the lateral ligaments of the ankle. In all specimens, the anterior talofibular ligament was supplied by the anterior branch of the peroneal artery and/or the lateral tarsal artery of the dorsalis pedis, while the posterior talofibular ligament was supplied by the posterior branch of the peroneal artery and/or the posterior tibial artery. The calcaneofibular ligament received variable contributions from the anterior and posterior branches of the peroneal artery, with few specimens receiving a contribution from the lateral tarsal or posterior tibial arteries. CLINICAL RELEVANCE: Understanding the vascular anatomy of the lateral ligament complex is beneficial when considering surgical management and may provide insight into factors that lead to chronic instability.

Trends of hip arthroscopy in the setting of acetabular dysplasia.

Hip arthroscopy is increasingly utilized in the treatment of symptomatic intra-articular hip pathology. Unaddressed development dysplasia of the hip (DDH) is thought to be associated with failure after hip arthroscopy. The aims of this study were (i) to identify the prevalence of previous failed hip arthroscopy in patients undergoing a periactebaular osteotomy (PAO) for the treatment of symptomatic acetabular dysplasia, (ii) report on the temporal trend of failed ipsilateral hip arthroscopy in patients undergoing PAO and (iii) to determine clinical and radiographic characteristics associated with utilization of isolated hip arthroscopy in patients with acetabular dysplasia. We identified 139 patients undergoing PAO who had a history of a prior ipsilateral hip arthroscopy. A comparison group of 1505 patients with a diagnosis of acetabular dysplasia, who underwent PAO alone without any prior ipsilateral surgery during the study period was used. Clinical characteristics, radiographic and intraoperative findings were compared between cohorts. From 2008 to 2015, the rate of previous failed hip arthroscopy in patients undergoing subsequent PAO increased steadily until 2013 with a maximum of 12%. Patients in the study group had mild dysplasia with significantly higher LCEA (17.2° versus 11.3°; P < 0.001) and ACEA (15.6° versus 10.8°; P < 0.001), a lower acetabular inclination (14.0° versus 19.0°; P < 0.001). The findings illustrate a constant increase in the rate of failed hip arthroscopy in the setting of acetabular dysplasia from 2008 till 2013. Female sex and mild dysplasia were associated with use of isolated hip arthroscopy in the setting of acetabular dysplasia.

Acetabular wedge augments for uncontained tibial plateau defects in revision total knee arthroplasty.

Tibial bone loss is a common scenario encountered during revision total knee arthroplasty. Reconstructive options depend on the amount and location of bone loss, but few good solutions exist to address large, uncontained tibial defects where cortical support is lost in the metadiaphyseal region. We describe a novel technique using acetabular augments to buttress a revision tibial component and recreate a hemiplateau during tibial revision total knee arthroplasty. In selected scenarios, this construct can create a biomechanically friendlier surface onto which to support the tibial tray and a less expensive option when compared to traditional stacked augments or cones. LEVEL OF EVIDENCE: IV-Case series.

The Arterial Anatomy of the Deltoid Ligament: A Cadaveric Study.

BACKGROUND: There is an increasing interest in the operative treatment of deltoid ligament disruption in the setting of chronic ankle instability. Understanding the vascular anatomy of the deltoid complex is beneficial when considering operative procedures on the medial ankle and may provide insight into factors that lead to chronic deltoid insufficiency and ankle instability. METHODS: Thirty-two pairs of cadaveric specimens (64 total legs) were amputated below the knee, and the tibialis anterior, tibialis posterior, and peroneal arteries were injected with India ink and Ward's blue latex. Specimens then underwent chemical debridement to identify the vascular supply to the deltoid ligament. A subset of specimens also underwent intraosseous debridement using the modified Spalteholz technique. RESULTS: The vascular supply to the deltoid ligament was clearly visualized in 60 (93.8%) specimens. Fifty-eight specimens (96.7%) had arterial supply with an origin from the medial tarsal artery, 57 specimens (95%) had supply from the tibialis posterior artery, and 23 (38.3%) specimens had supply from the tibialis anterior artery. All specimens had at least 1 location of intraosseous vascular supply, either at the medial malleolus or medial talus. CONCLUSION: There were 3 separate extraosseous sources and 2 intraosseous sources of vascular supply to the deltoid ligament. CLINICAL RELEVANCE: Knowledge of the vascular supply may aid in identifying factors that predispose a subset of patients with medial ankle sprains to failure of conservative treatment, as well as provide useful anatomic information when considering operative treatment for chronic ankle instability.

Does Use of a Variable Distal Femur Resection Angle Improve Radiographic Alignment in Primary Total Knee Arthroplasty?

BACKGROUND: The distal femur resection in total knee arthroplasty (TKA) is commonly made using a fixed angle relative to an intramedullary rod. This study's purpose was to assess if a variable distal femur resection angle technique improves femoral component alignment in TKA. METHODS: This was a review of primary TKAs performed by 2 surgeons. One surgeon used a fixed resection angle of 5° for varus and 3° for valgus knees ("fixed" cohort). The second used hip-knee-ankle (HKA) radiographs to measure the angle between the femoral anatomic axis and a line perpendicular to the femoral mechanical axis, which was used as the resection angle for each patient ("variable" cohort). Femoral component and HKA alignment were measured from standing HKA radiographs by 2, independent, blinded observers. Two hundred ninety patients were needed for power to detect a 15% difference in femoral component "outliers" (target of 0° ± 2°; significance = P < .05). RESULTS: Three hundred twenty consecutive patients were included with no differences in age, body mass index, or preoperative deformity (P = .3-.8). A 5° resection angle was used in 46.3% of the variable and 80.0% of the fixed cohort patients. A total of 80.2% of femoral components in the variable and 63.1% in the fixed cohort were within 0° ± 2° (P = .002; 84.6% of variable and 56.3% of fixed for valgus knees, P < .001). The mean HKA alignment was improved in the variable cohort (-1.4° ± 3.3° vs -2.6° ± 3.3°, P = .001). CONCLUSION: Use of a variable distal femur resection angle improves femoral component alignment after TKA.

Conversion of a failed hip resurfacing arthroplasty to total hip arthroplasty: pearls and pitfalls.

Surface replacement arthroplasty (SRA) remains a viable alternative to total hip arthroplasty (THA) in appropriately selected, active adults with degenerative hip disease. However, orthopedic surgeons are facing a number of scenarios where revision of one or both components of an SRA is indicated. Indications for revision vary and impact the potential outcomes of conversion of a SRA to THA. While clinical outcomes are generally favorable, a growing body of data illustrates patients who undergo conversion of a SRA to THA to be at increased risk of requiring a repeat revision surgery and experiencing functional outcomes inferior to that of a primary THA. The results of patients undergoing conversion of a SRA to THA highlight the need for careful patient selection, thorough preoperative counseling, and technical precision when performing a SRA. Furthermore, a systematic approach to the failed SRA is necessary to ensure optimal clinical results.

Contemporary Surgical Indications and Referral Trends in Revision Total Hip Arthroplasty: A 10-Year Review.

BACKGROUND: Revision total hip arthroplasty (THA) represents nearly 15% of all hip arthroplasty procedures in the United States and is projected to increase. The purpose of our study was to summarize the contemporary indications for revision THA surgery at a tertiary referral medical center. We also sought to identify the indications for early and late revision surgery and define the prevalence of outside institution referral for revision THA. METHODS: Using our institution's arthroplasty registry, we identified a retrospective cohort of 870 consecutive patients who underwent revision THA at our hospital from 2004 to 2014. Records were reviewed to collect data on patient's primary and revision THA procedures, and the interval between primary THA and revision surgery was determined. RESULTS: Aseptic loosening (31.3%), osteolysis (21.8%), and instability (21.4%) were the overall most common indications for revision THA and the most common indications for revision surgery within 5 years of primary THA. Aseptic loosening and osteolysis were the most common indications for revision greater than 5 years from primary THA. Only 16.4% of revised hips had their index arthroplasty performed at our hospital, whereas 83.6% were referred to our institution. CONCLUSIONS: Aseptic loosening, osteolysis, and instability remain the most common contemporary indications for revision THA in an era of alternative bearings and modular components. Most of our revisions were referred from outside institutions, which highlights the transfer of a large portion of the revision THA burden to tertiary referral centers, a pattern that could be exacerbated under future bundled payment models.

Gender Differences in Wear Rates for 28- vs 32-mm Ceramic Femoral Heads on Modern Highly Cross-linked Polyethylene at Midterm Follow-Up in Young Patients Undergoing Total Hip Arthroplasty.

BACKGROUND: We report on the midterm linear and volumetric wear of highly cross-linked polyethylene (HXLPE) and survivorship of 2 prospective young total hip arthroplasty (THA) cohorts that differed by the size of ceramic femoral head used: 28 vs 32 mm. METHODS: We prospectively analyzed 220 consecutive primary THAs in patients aged ≤50 years who received a cementless THA with a ceramic femoral head on HXLPE liner (C-HXLPE). There were 101 patients (46%) with 28-mm heads and 119 patients (54%) who received 32-mm heads at a mean follow-up of 5.5 years (range, 60-109 months). Wear was calculated using Martell Software. RESULTS: The 28-mm C-HXLPE cohort demonstrated average linear and volumetric wear of 0.020 mm/y (standard deviation [SD], 0.074; 95% CI, 0.003-0.037) and 18.775 mm(3)/y (SD, 21.743; 95% CI, 13.773-23.778) compared with 0.032 mm/y (SD, 0.087; 95% CI, 0.013-0.050]) and 29.847 mm(3)/y (SD, 35.441; 95% CI, 22.294-37.401) in the 32-mm C-HXLPE group. Subgroup analysis by gender and head size discovered significantly greater wear in females with 32-mm heads compared with 28-mm heads in both linear (0.01, 95% CI = -0.014 to 0.033 vs 0.048, 95% CI = 0.022-0.074 mm/y, P = .004) and volumetric wear (14.11, 95% CI = 8.957-19.271] vs 29.71, 95% CI = 17.584-41.840] mm(3)/y, P = .009). We found a 96% (95% CI = 92.30%-97.94%]) survivorship by Kaplan-Meier analysis at minimum 5 years with no failures because of osteolysis. CONCLUSIONS: Ceramic on HXLPE demonstrates extremely low wear properties in young patients at midterm follow-up. We identified a gender-dependent difference in wear based on head size, with 32-mm heads being associated with increased wear in females.

In Vivo Syndesmotic Overcompression After Fixation of Ankle Fractures With a Syndesmotic Injury.

OBJECTIVES: The goals of this study were to assess syndesmotic reductions using computerized tomography and to determine whether malreductions are associated with certain injury types or reduction forceps. DESIGN: Prospective cohort. SETTING: Urban level 1 trauma center. PATIENTS: Twenty-seven patients with operatively treated syndesmotic injuries were recruited prospectively. INTERVENTION: Patients underwent postoperative bilateral computerized tomography of the ankle and hindfoot to assess syndesmotic reduction. The uninjured extremity was used as a control. MAIN OUTCOME MEASUREMENT: Side-to-side differences of the fibular position within the tibial incisura were measured at several anatomic points and analyzed based on injury type, the presence of posterior malleolar injury, level of fracture, and type of reduction forceps used. RESULTS: On average, operatively treated syndesmotic injuries were overcompressed (fibular medialization) by 1 mm (P < 0.001) and externally rotated by 5° (P = 0.002) when compared with the uninjured extremity. The absence of a posterior malleolar injury and Weber B (OTA 44-B) fractures seemed to have a protective effect against malrotation, but not against overcompression. There was no difference in malreduction based on the type of the clamp used. CONCLUSIONS: It is possible, and highly likely based on these data, to overcompress the syndesmosis when using reduction forceps. Care should be taken to avoid overcompression, as this may affect the ankle motion and functional outcomes. To our knowledge, this is the first in vivo series of syndesmotic overcompression. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.