Taunton, Michael J.

Abstract Deep learning is revolutionizing medical imaging analysis by enabling the classification of various pathoanatomical conditions at scale. Unfortunately, there have been a limited number of accurate and efficient machine learning (ML) algorithms that have been developed for the diagnostic workup of morphological hip pathologies, including developmental dysplasia of the hip and femoroacetabular impingement. The current study reports on the performance of a novel ML model with YOLOv5 and ConvNeXt-Tiny architecture in predicting the morphological features of these conditions, including cam deformity, ischial spine sign, dysplastic appearance, and other abnormalities. The model achieved 78.0% accuracy for detecting cam deformity, 87.2% for ischial spine sign, 76.6% for dysplasia, and 71.6% for all abnormalities combined. The model achieved an Area under the Receiver Operating Curve of 0.89 for ischial spine sign, 0.80 for cam deformity, 0.80 for dysplasia, and 0.81 for all abnormalities combined. Inter-rater agreement among surgeons, assessed using Gwet’s AC1, was substantial for dysplasia (0.83) and all abnormalities (0.88), and moderate for ischial spine sign (0.75) and cam deformity (0.61).

AimsDistal femoral osteotomies (DFOs) are commonly used for the correction of valgus deformities and lateral compartment osteoarthritis. However, the impact of a DFO on subsequent total knee arthroplasty (TKA) function remains a subject of debate. Therefore, the purpose of this study was to determine the effect of a unilateral DFO on subsequent TKA function in patients with bilateral TKAs, using the contralateral knee as a self-matched control group.MethodsThe inclusion criteria consisted of patients who underwent simultaneous or staged bilateral TKA after prior unilateral DFO between 1972 and 2023. The type of osteotomy performed, osteotomy hardware fixation, implanted TKA components, and revision rates were recorded. Postoperative outcomes including the Forgotten Joint Score-12 (FJS-12), Tegner Activity Scale score, and subjective knee preference were also obtained at final follow-up.ResultsA total of 21 patients underwent bilateral TKA following unilateral DFO and were followed for a mean of 31.5 years (SD 11.1; 20.2 to 74.2) after DFO. The mean time from DFO to TKA conversion was 13.1 years (SD 9.7) with 13 (61.9%) of DFO knees converting to TKA more than ten years after DFO. There was no difference in arthroplasty implant systems employed in both the DFO-TKA and TKA-only knees (p > 0.999). At final follow-up, the mean FJS-12 of the DFO-TKA knee was 62.7 (SD 36.6), while for the TKA-only knee it was 65.6 (SD 34.7) (p = 0.328). In all, 80% of patients had no subjective knee preference or preferred their DFO-TKA knee. Three DFO-TKA knees and two TKA-only knees underwent subsequent revision following index arthroplasty at a mean of 12.8 years (SD 6.9) and 8.5 years (SD 3.8), respectively (p > 0.999).ConclusionIn this self-matched study, DFOs did not affect subsequent TKA function as clinical outcomes, subjective knee preference, and revision rates were similar in both the DFO-TKA and TKA-only knees at mean 32-year follow-up.Cite this article: Bone Jt Open 2024;5(11):1013–1019.

Abstract Periprosthetic fractures of the lesser trochanter may migrate proximally and result in anterior mechanical irritation and impingement with hip flexion refractory to comprehensive conservative management. In such cases, patients may benefit from arthroscopic resection of the displaced lesser trochanteric fragment. We present a minimally invasive, arthroscopic approach with initial access through an air bursogram. This technique can be performed percutaneously, with standard access cannulas, without the need for additional disposable instrumentation or large cannulas. In such a way, reproducible arthroscopic instrumentation can be provided for safe and efficient fragment removal while remaining cognizant of the nearby medial neurovascular bundle. Technique Video video See video under supplementary data.

Background There is a paucity of literature analyzing data for return to sport (RTS) and return to work (RTW) in the setting of direct anterior approach (DAA) total hip arthroplasty (THA). Objective The aims of this systematic review are to identify existing literature and to aggregate rates of RTS/RTW following DAA THA in a meta-analysis. Methods A query of major databases yielded 1819 initial studies. A random-effects model approach was implemented for meta-analysis. Moderator effects were assessed with respect to patient demographics and functional outcomes. Results Five studies reporting RTS after DAA THA were identified, representing a total of 204 patients with a mean age of 60.2±7.5 years and mean follow up of 31.8±9.5 months. Pooled rate of RTS was 76%(95% confidence interval [CI], 63%-86%;range 58%-100%). Pooled rate of return to the same sport was 77%(95%CI, 64%-86%;range of 62%-100%). Pooled rate of RTS to the same intensity was 58%(95%CI, 48%-68%;range of 41%-68%). Meta-regression demonstrated no significant correlations between independent variables and RTS characteristics. Three studies reported RTW rates. Rates of RTW within 3-months were 30%, 45%, and 60%. One study reported rate of RTW of 79% at 6-months and 87% at 12-months. One study demonstrated a mean time to RTW of 38±24.8 days. Conclusion Pooled rate of RTS is satisfactory following DAA THA and are comparable to rates of RTS aggregated without delineating surgical approach. Data supporting RTW rates following DAA THA limited, and thus more primary studies are needed to establish if this approach confers an advantage of faster RTS/RTW.

Background: Porous metaphyseal cones are frequently utilized during revision total knee arthroplasty (TKA) procedures. The purpose of the present study was to evaluate 3D-printed metaphyseal cones used for revision TKA, with specific emphasis on implant survivorship, radiographic appearance, and clinical outcomes after short-term follow-up. Methods: We identified 740 cones (498 tibial, 242 femoral) that had been inserted during 533 revision TKA procedures that had been performed at a single tertiary care academic institution. Aseptic loosening (n = 199), periprosthetic joint infection (PJI) (n = 183), and instability (n = 84) were the most common reasons for the index revision. Type-2B or 3 bone loss was present in 67% of the knees. The mean age was 66 years, the mean body mass index was 34 kg/m 2 , and 55% of the patients were female. Serial radiographs were reviewed. The mean duration of follow-up was 4 years. Results: The 5-year cumulative incidence of cone revision for aseptic loosening was 1% (95% confidence interval [CI], 0% to 3%). The 5-year cumulative incidence of any cone revision or removal was 6% (95% CI, 4% to 9%). In total, 37 cones (19 femoral, 18 tibial) were revised, with PJI (n = 23; 14 recurrent), periprosthetic femoral fracture (n = 3), arthrofibrosis (n = 3), and aseptic loosening of the femoral component and femoral cone (n = 3) as the most common reasons for cone revision. The 5-year cumulative incidence of any TKA re-revision was 14% (95% CI, 11% to 18%). There were a total of 67 re-revisions, with PJI (n = 38), persistent drainage (n = 6), and extensor mechanism disruption (n = 3) being the most common reasons. Radiographically, 2 unrevised femoral cones and 1 unrevised tibial cone appeared to be possibly loose; all 3 cones were in knees with distal femoral replacements or hinged constructs. Conclusions: This large series showed that 3D-printed titanium metaphyseal cones were very durable at short-term follow-up, with a 5-year cumulative incidence of cone revision for aseptic loosening of 1%. PJI was the most common reason for cone revision and any revision. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

AimsDual-mobility (DM) components are increasingly used to prevent and treat dislocation after total hip arthroplasty (THA). Intraprosthetic dissociation (IPD) is a rare complication of DM that is believed to have decreased with contemporary implants. This study aimed to report incidence, treatment, and outcomes of contemporary DM IPD.MethodsA total of 1,453 DM components were implanted at a single academic institution between January 2010 and December 2021: 695 in primary and 758 in revision THA. Of these, 49 presented with a dislocation of the large DM head and five presented with an IPD. At the time of closed reduction of the large DM dislocation, six additional IPDs occurred. The mean age was 64 years (SD 9.6), 54.5% were female (n = 6), and mean follow-up was 4.2 years (SD 1.8). Of the 11 IPDs, seven had a history of instability, five had abductor insufficiency, four had prior lumbar fusion, and two were conversions for failed fracture management.ResultsThe incidence of IPD was 0.76%. Of the 11 IPDs, ten were missed either at presentation or after attempted reduction. All ten patients with a missed IPD were discharged with a presumed reduction. The mean time from IPD to surgical treatment was three weeks (0 to 23). One patient died after IPD prior to revision. Of the ten remaining hips with IPD, the DM head was exchanged in two, four underwent acetabular revision with DM exchange, and four were revised to a constrained liner. Of these, five (50%) underwent reoperation at a mean 1.8 years (SD 0.73), including one additional acetabular revision. No patients who underwent initial acetabular revision for IPD treatment required subsequent reoperation.ConclusionThe overall rate of IPD was low at 0.76%. It is essential to identify an IPD on radiographs as the majority were missed at presentation or after iatrogenic dissociation. Surgeons should consider acetabular revision for IPD to allow conversion to a larger DM head, and take care to remove impinging structures that may increase the risk of subsequent failure.Cite this article: Bone Joint J 2024;106-B(5 Supple B):98–104.

Purpose To report the clinical outcomes and reoperation rates of arthroscopic and endoscopic iliopsoas release at short‐term follow‐up after ipsilateral total hip arthroplasty (THA) at 2 separate medical institutions and to evaluate whether demographic and radiographic parameters are associated with postoperative patient‐reported outcomes (PROs). Methods Patients with iliopsoas tendinitis in the setting of prior THA who underwent arthroscopic iliopsoas fractional lengthening from 1988 to 2023 at 2 academic institutions were reviewed. Patients were included if they had 12 months of follow‐up and underwent evaluation of preoperative anterior acetabular component overhang, surgery satisfaction, postoperative subjective hip flexion strength and anterior groin pain improvement, modified Harris Hip Score, Single Assessment Numeric Evaluation score, Tegner activity scale score, visual analog scale (VAS) score, and revision hip arthroplasty. Results Sixty hips in 58 patients (19 male and 39 female patients) were followed up for a mean of 39.3 months (range, 12.0‐105.9 months) postoperatively. Of the patients, 77% reported feeling “much better” or “slightly better,” 75% reported improved anterior groin pain, and 60% reported improved subjective hip flexion strength. The surgery satisfaction rating was 7.2 ± 3.3 (scale of 0 to 10). The mean postoperative modified Harris Hip Score, VAS score for pain at rest, VAS score for pain with use, and Single Assessment Numeric Evaluation score were 73.9 ± 19.4, 1.3 ± 2.4, 3.8 ± 2.9, and 71.9 ± 21.9, respectively. Preoperative anterior acetabular component overhang was 3.3 ± 6.5 mm and did not significantly correlate with postoperative PROs ( P ≥ .45). The Tegner score improved from 2.5 ± 1.7 preoperatively to 2.9 ± 1.4 postoperatively ( P = .0253). Three patients underwent revision arthroplasty at a mean of 25.3 months (range, 11.6‐40.4 months) postoperatively, with an acetabular component revision rate of 3.3%. Conclusions Satisfactory outcomes and low revision arthroplasty rates were observed in patients undergoing arthroscopic iliopsoas lengthening after THA. There was no statistically significant relation between anterior acetabular component overhang and final PROs. Level of Evidence Level IV, therapeutic case series.

Abstract Background Massive modular endoprostheses have become a primary means of reconstruction after oncologic resection of a lower extremity tumor. These implants are commonly made with cobalt-chromium alloys that can undergo wear and corrosion, releasing cobalt and chromium ions into the surrounding tissue and blood. However, there are few studies about the blood metal levels in these patients. Question/purpose What is the whole blood cobalt and chromium ion level in patients with massive modular endoprostheses? Methods We performed a cross-sectional study of our total joints registry to identify patients with a history of an endoprosthetic reconstruction performed at our institution. Patients who were alive at the time of our review in addition to those undergoing an endoprosthetic reconstruction after an oncologic resection were included. Whole blood samples were obtained from 27 (14 male and 13 female) patients with a history of a lower extremity oncologic endoprosthesis. The median time from surgery to blood collection was 8 years (range 6 months to 32 years). Blood samples were collected and stored in metal-free ethylenediaminetetraacetic acid tubes. Samples were analyzed on an inductively coupled plasma mass spectrometer in an International Organization for Standardization seven-class clean room using polytetrafluoroethylene-coated instruments to reduce the risk of metal contamination. The analytical measuring range was 1 to 200 ng/mL for chromium and cobalt. Cobalt and chromium levels were considered elevated when the blood level was ≥ 1 ppb. Results Cobalt levels were elevated in 59% (16 of 27) of patients, and chromium levels were elevated in 26% (seven of 27). In patients with elevated metal ion values, 15 of 17 patients had a reconstruction using a Stryker/Howmedica Global Modular Replacement System implant. Conclusion Blood metal levels were elevated in patients who received reconstructions using modular oncology endoprostheses Future work is needed to establish appropriate follow-up routines and determine whether and when systemic complications occur because of elevated metal levels and how to potentially address these elevated levels when complications occur. Prospective and retrospective collaboration between multiple centers and specialty societies will be necessary to address these unknown questions in this potentially vulnerable patient group. Level of Evidence Level IV, therapeutic study.

Background: Dual-mobility (DM) implants reduce the risk of dislocation in patients who have undergone total hip arthroplasty (THA); however, DM implants are at risk for large-head dislocation and intraprosthetic dissociation (IPD), where the inner femoral head dissociates from the outer polyethylene head. This study aimed to report the incidence of DM dislocation and IPD, evaluate the rate of recognition of IPD before and after reduction, investigate the outcomes of these complications, and provide treatment recommendations for their management. Methods: Between 2010 and 2021, 695 primary and 758 revision THAs were performed with DM constructs at a single institution. There were 44 large-head dislocations (3.0%) and 10 IPDs (0.7%). Four additional IPDs occurred during attempted closed reduction, increasing the IPD incidence to 0.96%. We reviewed prior instability history, dislocation management, success of reduction, recognition of IPD, and subsequent rates of revision and complications. The mean follow-up was 2.5 years. Results: Nine of 10 IPDs were missed at presentation and thus not treated as such. Sixty-three percent of attempted closed reductions in the emergency department failed and led to 4 IPDs and 1 periprosthetic fracture. Reduction success was associated with the following factors: use of general anesthesia with paralysis (p = 0.02), having the reduction performed by an orthopaedist (p = 0.03), and undergoing only 1 reduction attempt (p = 0.015). Two-thirds of dislocations required revision. The rate of redislocation was 33%, and 5 hips required subsequent revision at a mean of 1.8 years after the initial dislocation. Conclusions: We present an evaluation of DM-implant dislocation and dissociation along with management recommendations based on these data. Given the low success and high complication rates of attempted closed reduction and the need for eventual revision, we recommend that all patients with dislocated DM implants be brought to the operating room for closed reduction as well as potential revision if the reduction fails. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.