The February 2025 Hip & Pelvis Roundup. 360. looks at: Postoperative periprosthetic femoral fractures after hip arthroplasty: quantifying the other half of the picture; Hip arthroscopy in patients with borderline dysplasia: how do we know when it will not work?; The morbidly obese patient remains a challenge for arthroplasty surgeons; Unexpected positive cultures in aseptic revision hip and knee arthroplasty: does it make a difference?; Failed spinal anaesthesia in hip and knee arthroplasty surgery; Clinical failure of femoral neck fracture is associated with varus necks; Navigating the angles: how variations in femoral and acetabular versions influence hip pain and treatment; High-tech or hands-on? Similar outcomes in direct anterior total hip arthroplasty

Short stems have been developed to conserve bone stock, especially in younger populations undergoing a total hip arthroplasty (THA), and showed similar functional outcomes compared to conventional stems. Recent literature suggested that stem length might be an independent risk factor for acute periprosthetic femoral fracture in direct anterior THA (1) or with different short stem designs (2). The purpose of the present study was to compare the incidence of acute periprosthetic femoral fractures, between stems of the same manufacture (Taperloc microplasty vs Taperloc complete), which have the same stem characteristics, except for the stem length which is 35 mm shorter in Taperloc microplasty during posterior and lateral THA. Our institution's arthroplasty database was searched for all primary total hip arthroplasties utilizing short femoral stems performed between August 2016 and August 2023. Pre-operative X-rays for each case were analysed to characterize the proximal femoral geometry, specifically the canal bone ratio (CBR) and canal flare index (CFI). Data analysis was performed to identify risk factors for periprosthetic fractures. For the time period assessed, 2107 femoral stems (Taperloc Microplasty:1727, Taperloc complete: 380) were implanted. Females constituted 53% of the cohort. The average patient age was 70±11 years. The periprosthetic fracture rate was 0.94%, with 20 periprosthetic fractures (Taperloc Microplasty:17, Taperloc complete: 3) excluding 2 greater trochanteric fractures (1 at each group), identified at follow-up of three months. There was no significant difference between the periprosthetic fracture rates between the two stems (0.98% vs 0.79%, p>0.72) The multivariate regression analysis demonstrated that the stem length, CBR, CFI, age, and gender were not risk factors for periprosthetic fracture. The present study demonstrated that both Taperloc Microplasty and Taperloc complete stems had similar rates of periprosthetic fractures, and the stem length was not a risk factor for a periprosthetic fracture during uncemented THA. 1. Tamaki T, Cementless Tapered-Wedge Stem Length Affects the Risk of Periprosthetic Femoral Fractures in Direct Anterior Total Hip Arthroplasty. J Arthroplasty. 2018 Mar;33(3):805-809. 2. Staunton P. Acute Periprosthetic Hip Fracture with Short Uncemented Femoral Stems. J Arthroplasty 2024 accepted

Background

There is increasing impetus to use rapid recovery care pathways when treating patients undergoing total hip arthroplasty (THA). The direct anterior (DA) approach is a muscle sparing technique that is believed to support these new pathways. Implants designed for these approaches are available in both collared and collarless variations and understanding the impact each has is important for providing the best treatment to patients.

Utilization of C-arm fluoroscopy during direct anterior total hip arthroplasty (THA) is disruptive and potentially increases the risks of patient infection and cumulative surgeon radiation exposure. This pilot study evaluated changes in surgeon C-arm utilization during an initial 10 cases of direct anterior THA in which an imageless computer-assisted navigation device was introduced. This retrospective study includes data from 20 direct anterior THA cases performed by two orthopaedic surgeons (BC; SRE) in which an imageless computer-assisted navigation device was utilized (Intellijoint HIP®; Intellijoint Surgical, Waterloo, ON, Canada). Total C-arm image count was recorded in each case, and cases were grouped in sets of 5 for each surgeon. The mean C-arm image count was calculated for each surgeon, and combined C-arm image counts were calculated for the study cohort. Student's t-tests were used to assess differences. The use of intraoperative C-arm fluoroscopy decreased from a mean of 9.4 images (standard deviation [SD]: 8.6; Range: 3 – 23) to a mean of 2 images (SD: 2.9; Range: 0 – 7) for surgeon BC (P=0.10) and decreased from a mean of 10.75 images (SD: 1.2; range 9 – 12) to a mean of 6.7 images (SD: 8.3; range: 0 – 16) for surgeon SRE (P=0.36). Combined, an overall decrease in intraoperative C-arm image count from a mean of 11.3 images (SD: 6.9; range: 6 – 23) to a mean of 3.7 images (SD: 3.9; range: 0 – 8.5) was observed in the study cohort (P=0.06). The adoption of imageless computer-assisted navigation in direct anterior THA may reduce the magnitude of intraoperative C-arm fluoroscopy utilization; however further analysis is required

Introduction. Perioperative hospital adverse events are an issue that every surgeon endeavors to avoid and minimize as much as possible. Even “minor events” such as fever or tachycardia may lead to significant costs due to workup tests, inter-consultations, and/or increased hospital stay. The objective of this study was compare perioperative outcomes (hospital length of stay [LOS], discharge disposition), rates of in-hospital adverse events and transfusion, and postoperative readmission and reoperation rates for simultaneous and staged bilateral direct anterior total hip arthroplasty (DA-THA) patients. Methods. A retrospective chart review was conducted on a consecutive series of 411 primary bilateral DA-THAs performed between 2010 and 2016 at a single institution by two fellowship trained surgeons. These were categorized as: (1) simultaneous (same anesthesia, n=122) and (2) staged (different hospitalizations, n=289). The mean time between staged surgeries was 468 days (± 414 days). Baseline patient demographics as well as hospital LOS, discharge disposition (home vs. other), hospital adverse events (i.e., nausea, vomiting, tachycardia, fever, confusion, pulmonary embolism, etc.), blood transfusions, and unplanned hospital readmissions and reoperations within 90 days were collected. Groups were compared using independent –tests, Fisher's exact test, and Pearson Chi-Square. Results. Overall, the baseline patient characteristics of the simultaneous DA-THA group had significantly younger patients, a higher proportion of males, and twice the proportion of patients with ASA 1 status compared with the staged DA-THA group. The simultaneous group showed statistically significant longer LOS (2.6 vs. 1.8 days, p<0.001) and an increased proportion of patients discharged to an extended care facility (23% vs. 5.9%, p<0.001). The overall rate of hospital adverse events in the series was 136/411 (33.1%), with a higher rate in the simultaneous DA-THA patients (54.1% vs. 24.2%, p<0.001). Transfusion rate was higher in the simultaneous DA-THA group (45.9%) compared to the staged group (6.9%) (p<0.001). There were no readmissions and a single reoperation in the staged DA-THA group at 90 days postoperative. Conclusion. These data show that bilateral DA-THAs performed in a staged fashion, rather than simultaneously, have a shorter hospital LOS and decreased rates of hospital adverse events and transfusions

Background. Despite growing interest in direct anterior approach total hip arthroplasty, perioperative femoral fracture and early aseptic loosening are increasingly recognized complications. Previous research has documented the role of surgeon experience in association with these femoral complications. The purpose of this study was to explore the relationship between femoral component design and early periprosthetic femoral complications. Methods. This was an extension of previous work with an updated patient cohort of 5090 consecutive direct anterior primary total hip arthroplasties at a single institution with a single-taper, wedge femoral stem with 4 variants involving length and geometry: Group 1) full length, standard profile; Group 2) full length, reduced distal profile; Group 3) short length, standard profile; and Group 4) short length, reduced distal profile. Records were reviewed retrospectively for the incidence of early periprosthetic fracture or aseptic loosening and analyzed with regard to patient demographics and femoral stem type. Results. There were 42 (0.83%) periprosthetic femur complications observed in the early postoperative period. Increased age (p<0.001) and female gender (p=0.023) were significantly associated with incidence of femoral complications in univariate analysis, while age maintained this significant relationship in multivariate analysis (P<0.001). There was a trend toward increased complication rate in patients receiving a short stem with full profile taper (1.27%, p=0.0539). Conclusion. Despite an overall low rate of femoral complications after direct anterior total hip arthroplasty, the risk is increased in elderly patients and females. Furthermore, femoral stem design may portend an elevated risk of these complications

Introduction. The rate of total hip arthroplasty (THA) surgery continues to dramatically rise in the United States, with over 300,000 procedures performed in 2010. Although a relatively safe procedure, THA is not without complications. These complications include acetabular fracture, heterotopic ossification, implant failure, and nerve palsy to name a few. The rates of neurologic injury for a primary THA are reported as 0.7–3.5%. These rates increase to 7.6% for revision THA. The direct anterior total hip arthroplasty (DATHA) is gaining popularity amongst orthopedic surgeons. Many of these surgeons elect to use the Hana® table during this procedure for optimal positioning capability. Although intraoperative mobility and positioning of the hip joint during DATHA improves operative access, select positions of the limb put certain neurologic structures at risk. The most commonly reported neurologic injuries in this regard are to the sciatic and femoral nerves. To our knowledge, the use of neuromonitoring during DATHA, especially those using the Hana® table, has not been described in the literature. Methods. The patient was a 60-year-old male with long standing osteoarthritis of the right hip and prior left THA. Somatosensory evoked potential (SSEP) leads were placed bilaterally into the hand (ulnar nerve) as well as the popliteal fossae (posterior tibial nerve). Unilateral electromyography leads were placed into the vastus medialis obliquus, biceps femoris, gastrocnemius, tibialis anterior, and abductor hallucis of the operative limb (Fig. 1). Once the patient was sterilely draped, a direct anterior Smith-Peterson approach to the hip was used. Results. After the patient completed standard pre-operative protocol, neuromonitoring leads were placed as described above. There were no complications, neuromonitoring remained stable from baseline, and the patient tolerated the procedure well. Moreover, the senior author routinely uses a prophylactic cable around the calcar, particularly in patients with osteoporotic bone, as was the case with this patient. The patient's post-operative course has been without complications as well. Conclusion. There are a few studies that have examined the pressure changes around the femoral nerve during a DATHA and found that the nerve was at most danger with misplacement of a retractor near the anterior lip of the acetabulum. Furthermore, the popularity of DATHA and the Hana® table make neuromonitoring more amenable for use since the whole limb does not need to be sterilely prepped as with other approaches to the hip. The reported rates of neurologic injury during any THA along with those developed from passage of prophylactic cerclage cables and the goals of reducing surgical complications make this novel technique intriguing. It allows the surgeon yet another safe and effective tool to decrease the likelihood of neurologic injury during DATHA. For any figures or tables, please contact the authors directly

Introduction. Iliopsoas impingement is a well described cause of groin pain after direct anterior total hip arthroplasty (THA). We proposed to evaluate the incidence, natural history and response to treatment of iliopsoas impingement after direct anterior total hip arthroplasty. Methods. A retrospective chart review of 725 consecutive patients who underwent anterior approach total hip arthroplasty between 2009 and 2014 was conducted. All surgeries were performed by one of two surgeons. Patients were included if they underwent primary anterior approach THA and had a minimum of 2 years of follow up. Patients who had a posterior approach, revision surgery or had less than 2 years of follow up were excluded. Iliopsoas impingement was identified if patients reported groin pain at greater than 6 weeks of postoperative follow up and in association with pain with resisted seated hip flexion. The natural history and response to treatment was recorded for patients identified as having iliopsoas impingement. Results. 900 patients met inclusion criteria. Of these, 120 (13.4%) developed groin pain following direct anterior total hip arthroplasty. The average time of onset was at 21 months postoperatively. At 2 years postoperatively, 16% of patients had symptoms, whereas 84% had resolution. 28% of patients responded to structured physical therapy, 22% improved with home stretching, 19% improved after arthroscopic psoas release, 9% after psoas sheath injection, and 6% required acetabular component revision. Conclusion. In our study population, iliopsoas impingement is not an uncommon finding after direct anterior total hip arthroplasty, but nearly half of these patients responded well to home stretching or physical therapy. In some cases, psoas injection and arthroscopic release was necessary. Rarely, cup revision was required for symptomatic relief

The direct anterior (DA) approach for total hip arthroplasty (THA) has become increasingly popular in North America. With experience, exposure of both the acetabulum and femur can be achieved similar to those in other approaches. In cases of difficult femoral exposure, the conjoint tendon of the short external rotators can be released to improve visualisation. The effect of conjoint tendon release has not been previously explored in regards to overall outcomes, or postoperative pain. The goal of this study was to evaluate 1) the length of stay and inpatient pain medication requirements of patients undergoing DA THA on the basis of conjoint tendon release, and 2) whether conjoint tendon release influenced functional outcomes.

We conducted a retrospective chart review of all cases of primary DA THAs conducted by single surgeon at LHSC University between August 2012 and July 2015. Patient demographics, bilateral THA cases, intraoperative conjoint tendon or other soft tissue releases, intra-operative complications, and length of stay (LOS) were evaluated for all cases. Inpatient pain medication data was available for all cases from Apr 2014 onwards. One year functional outcome scores, including WOMAC and Harris Hip Scores (HHS), were evaluated for all cases before August 2014. Six-week and three-month functional outcome scores were available and evaluated for a subset of cases. All data was analysed with multiple linear regression.

Three hundred and twelve cases of primary DA THAs were identified, of which 29 were concurrent bilateral THAs. One hundred and eighty cases included a conjoint tendon release, while 29 cases had other soft tissue releases (tensor fascia lata). Mean age and BMI were 64.9±11.5 years and 29.0±5.3 respectively. Mean LOS was 1.3±1.1 days, with age, bilateral THA, non-conjoint tendon soft tissue release, and intra-operative complications being predictive of LOS (p<0.05). Pain medication data was available for 107 cases, of which 11 were concurrent bilateral THAs. Sixty four cases included a conjoint tendon release, while one case had other soft tissue releases. Mean daily morphine equivalent dose (MED) narcotic use was 43.2±48.2mg, with age being a negative predictor of narcotic use (p<0.05). BMI was a negative predictor of one year HHS pain, HHS total, and all WOMAC subcategory scores, while age was a negative predictor of one year HHS function and HHS total scores (p<0.05). None of the variables were predictive of six-week and three-month functional outcome scores. Conjoint tendon release was not predictive of LOS, inpatient pain medication requirements, or outcome scores.

Conjoint tendon release did not affect postoperative pain, LOS, or functional outcomes. Given that conjoint release improves femoral exposure, intraoperative thresholds for conjoint release should be low. The effect of intraoperative release of other soft tissues is uncertain, as this increased LOS but not postoperative pain.

Background

In total hip arthroplasty (THA), the importance of preserving muscle is widely recognized. It is important to preserve the short external rotator muscles because they contribute to joint stability and prevent postoperative dislocation. However, despite careful capsular release and femoral rasping, damage to the short external rotator muscles may occur. The Optymis Shot Stem preserves more bone and surrounding tissue than does a traditional primary stem. We investigated the usefulness of the stem in terms of the extent of preservation of the tendon attachment on the greater trochanter.

In minimally invasive direct anterior total hip arthroplasty double offset broach handles are used, in order to facilitate the preparation of the femoral canal. The maximum value of the main force peak and the impulse of two types of double offset broach handles (A European version, B American version) were compared to a single offset broach handle (S). Results have demonstrated that the highest values of the main force peak and force impulse were found in the single offset broach handle. Broach handle A had higher impulse values and lower maximum force values compared to broach handle B. In double offset broach handles less energy is transmitted to the tip. Broach handle A has a lower force peak than B and therefore a reduced risk of bone fracture

Purpose: LFCN neuropraxia is a known complication of the anterior approach to the hip joint. The objective of this study was to define the incidence, functional impact and natural history of this neuropraxia in the anterior approach after both hip resurfacing (HR) and primary total hip arthroplasty (THA). Method: Between September 2006 and January 2008, 132 consecutive patients underwent a direct anterior hip approach (DAA) (55 THR; 77 HR). Sixty-two patients were female and 70 were male; the mean age was 55.54 (range, 29.9 to 88.7). Self reported questionnaires for sensory deficits of LFCN, a neuropathic pain score (DN4) as well as SF-12, UCLA and WOMAC scores were completed. A subset of 60 patients (30 THA, 30 resurfacing) was evaluated at two time intervals (6 and 12 months). Results: One hundred and seven patients (81%) reported LFCN neuropraxia, with a mean severity score of 2.32/10 (SD, 2.11); mean DN4 score of 2.42/10 (SD, 2.37). Hip resurfacing had a higher incidence of neuro-praxia compared to THA: 91% versus 67% (p=0.02), respectively. No functional limitations were reported on SF-12, WOMAC or UCLA scores. Of the subset of 60 patients, 53 (88.3%) reported neuropraxia at the six month follow-up interval with only three (5.7%) having complete resolution at 12 months. Patients who reported neuropraxia at both testing intervals did report an improvement in DN4 scores: 3.6 versus 2.5 at 6 and 12 months, respectively (p=0.02). Conclusion: Although LFCN neuropraxia is a frequent complication after DAA total hip arthroplasty, it does not lead to any functional limitations. A decrease in symptoms does occur over time, with only a small number of patients reporting complete resolution