Perioperative Cefazolin for Total Joint Arthroplasty Patients Who Have a Penicillin Allergy: Is It Safe?

BACKGROUND: Cefazolin is the standard of care for perioperative antibiotic prophylaxis in total joint arthroplasty (TJA) in the United States. The potential allergic cross-reactivity between cefazolin and penicillin causes uncertainty regarding optimal antibiotic choice in patients who have a reported penicillin allergy (rPCNA). The purpose of this study was to determine the safety of perioperative cefazolin in PCNA patients undergoing primary TJA. METHODS: We identified all patients (n = 49,842) undergoing primary total hip arthroplasty (n = 25,659) or total knee arthroplasty (n = 24,183) from 2016 to 2022 who received perioperative intravenous antibiotic prophylaxis. Patients who had an rPCNA (n = 5,508) who received cefazolin (n = 4,938, 89.7%) were compared to rPCNA patients who did not (n = 570, 10.3%), and to patients who did not have an rPCNA (n = 43,359). The primary outcome was the rate of allergic reactions within 72 hours postoperatively. Secondary outcomes included the rates of superficial infections, deep infections, and Clostridioides difficile infections within 90 days. RESULTS: The rate of allergic reactions was 0.1% (n = 5) in rPCNA patients who received cefazolin, compared to 0.2% (n = 1) in rPCNA patients who did not (P = .48) and 0.02% (n = 11) in patients who have no rPCNA (P = .02). Allergic reactions were mild in all 5 rPCNA patients who received cefazolin and were characterized by cutaneous symptoms (n = 4) or dyspnea in the absence of respiratory distress (n = 1) that resolved promptly with antibiotic discontinuation and administration of antihistamines and/or corticosteroids. We observed no differences in the rates of superficial infections (0.1 versus 0.2%, P = .58), deep infections (0.3 versus 0.4%, P = .68), or C difficile infections (0.04% versus 0%, P = .99) within 90 days in rPCNA patients who received cefazolin versus alternative perioperative antibiotics. CONCLUSIONS: In this series of more than 5,500 patients who had an rPCNA undergoing primary TJA, perioperative prophylaxis with cefazolin resulted in a 0.1% incidence of allergic reactions that were clinically indolent. Cefazolin can be safely administered to most patients, independent of rPCNA severity. LEVEL OF EVIDENCE: III.

Pairing 40-mm Femoral Heads With the Smallest Compatible Acetabular Components in Total Hip Arthroplasty: Mid-Term Outcomes in 177 Cases.

BACKGROUND: Contemporary total hip arthroplasty (THA) often employs larger femoral heads to optimize hip stability. However, pairing 40-mm femoral heads with the smallest compatible acetabular components poses a potential risk for implant failure. The purpose of this study is to evaluate the outcomes of primary THAs using 40-mm femoral heads and the smallest compatible acetabular components. METHODS: Between 2007 and 2018, 177 primary THAs involving 40-mm femoral heads and acetabular components ≤56 mm with highly cross-linked polyethylene liners were identified. Mean age was 61 years, 56% were females, and mean body mass index was 32 kg/m2. Cumulative incidences of dislocation, any revision, and any reoperation were determined utilizing a competing risk model. Osteolysis and femoral head penetration were assessed at minimum 8-year follow-up (n = 16). Mean follow-up was 6 years. RESULTS: There were no cases of liner fractures or dissociations. The 10-year cumulative incidences of dislocation, any revision, and any reoperation were 3.6%, 4.2%, and 6.8%, respectively. Mean linear femoral head penetration was 0.01 mm/y and mean volumetric wear rate was 50 mm3/y. One THA demonstrated stable, asymptomatic periacetabular radiolucent lines at most recent follow-up. CONCLUSION: In 177 primary THAs pairing 40-mm femoral heads with the smallest compatible acetabular components, there were no liner fractures or dissociations. The cumulative incidence of dislocation was modest at 10 years. The cumulative incidences of any revision and any reoperation were low at mid-term. LEVEL OF EVIDENCE: IV.

Extended Oral Antibiotic Prophylaxis After Aseptic Revision Total Hip Arthroplasty: Does It Decrease Infection Risk?

BACKGROUND: Extended oral antibiotic prophylaxis (EOA) has been shown to reduce infection after high-risk primary total hip arthroplasties (THAs) and reimplantations. However, data are limited regarding EOA after aseptic revision THAs. This study evaluated the impact of EOA on infection-related outcomes after aseptic revision THAs. METHODS: We retrospectively identified 1,107 aseptic revision THAs performed between 2014 and 2019. Patients who received EOA >24 hours perioperatively (n = 370) were compared to those who did not (n = 737) using an inverse probability of treatment weighting model. Their mean age was 65 years (range, 19-98 years), mean body mass index was 30 kg/m2 (range, 16-72), and 54% were women. Outcomes included cumulative probabilities of any infection, periprosthetic joint infection (PJI), and re-revision or reoperation for infection. Mean follow-up was 4 years (range, 2-8 years). RESULTS: The cumulative probability of any infection after aseptic revision THA was 2.3% at 90 days, 2.7% at 1 year, and 3.5% at 5 years. The cumulative probability of PJI was 1.7% at 90 days, 2.1% at 1 year, and 2.8% at 5 years. There was a trend toward an increased risk of any infection (hazards ratio [HR] = 2.6; P = .058), PJI (HR = 2.6; P = .085), and re-revision (HR = 6.5; P = .077) or reoperation (HR = 2.3; P = .095) for infection in patients who did not have EOA at the final clinical follow-up. CONCLUSIONS: EOA after aseptic revision THA was not associated with a statistically significant decreased risk of any infection, PJI, or re-revision or reoperation for infection at all time points. LEVEL OF EVIDENCE: Level III.

Extended Oral Antibiotic Prophylaxis After Aseptic Revision TKA: Does It Decrease Infection Risk?

BACKGROUND: Extended oral antibiotic prophylaxis (EOA) has been shown to potentially reduce infection rates after high-risk primary total knee arthroplasties (TKAs) and reimplantations. However, data is limited regarding EOA after aseptic revision TKAs. This study evaluated the impact of EOA on infection-related outcomes after aseptic revision TKAs. METHODS: 904 aseptic revision TKAs from 2014-2019 were retrospectively identified. Patients who received EOA >24 hours perioperatively (n = 267) were compared to those who did not (n = 637) using an inverse probability of treatment weighting model. Mean age was 66 years, mean BMI was 33 kg/m2, and 54% were female. Outcomes included cumulative probabilities of any infection, periprosthetic joint infection (PJI), superficial infection, and re-revision or reoperation for infection. RESULTS: The cumulative probability of any infection after aseptic revision TKA was 1.9% at 90 days, 3.5% at 1 year, and 8.1% at 5 years. Patients without EOA had a higher risk of any infection at 90 days (HR = 7.1; P = .01), but not other time points. The cumulative probability of PJI after aseptic revision TKA was 0.8% at 90 days, 2.3% at 1 year, and 6.5% at 5 years. Patients without EOA did not have an increased risk of PJI. There were no differences in re-revision or reoperation for infection at any time point between groups. CONCLUSION: Extended oral antibiotics after aseptic revision TKA were associated with a 7-fold decreased risk of any infection at 90 days. The results suggest a potential role for EOA after aseptic revision TKA and warrant additional prospective studies. LEVEL OF EVIDENCE: Level III.

Comparison of all-polyethylene and metal-backed modular tibial components in endoprosthetic reconstruction of the distal femur.

INTRODUCTION: All-polyethylene (AP) tibial components have demonstrated equivalent or improved long-term survivorship and reduced cost compared with metal-backed (MB) components in primary total knee arthroplasty; however, there is a lack of data comparing these outcomes in the setting of an oncologic endoprosthetic reconstruction. METHODS: A total of 115 (88 AP:27 MB) patients undergoing cemented distal femur endoprosthetic reconstruction following oncologic resection were reviewed. Mean age was 40 years and 51% were females. Cumulative incidences of all-cause revision, tibial component revision, reoperation, and infection were calculated utilizing a competing risk analysis with death as the competitor. Mean follow-up was 14 years. RESULTS: The 10-year cumulative incidence of all-cause revision was 19.9% in the AP group and 16.3% in the MB group (hazard ratio [HR] = 0.93, p = 0.88). The cumulative incidence of tibial component revision was significantly lower in AP compared with MB at 10 years (1.1% vs. 12.5%, HR = 0.18, p = 0.03). There was no difference in infection-free survival when comparing the two groups (p = 0.72). CONCLUSIONS: Reconstruction utilizing an MB or AP tibia component resulted in equivalent overall outcome; however, the tibial component in the AP group was less likely to be revised. AP tibial component should be considered for all primary oncologic reconstructions in the distal femur. LEVEL OF EVIDENCE: Level III Therapeutic.

Comparison of reconstructive techniques following oncologic intraarticular resection of proximal humerus.

INTRODUCTION: The proximal humerus is a common site of primary and metastatic disease in the upper extremity. Historically, the goal of a hemiarthroplasty reconstruction was to provide a stable platform for hand and elbow function, with limited shoulder function. Techniques utilizing a reverse endoprosthesis (endoprosthetic replacement [EPR]) and allograft-prosthetic composite (APC) have been developed; however, there is a paucity of comparative studies. METHODS: A total of 83 (42 females, 41 males) patients undergoing an intraarticular resection of the humerus were reviewed. Reconstructions included 30 reverse and 53 hemiarthroplasty; including hemiarthroplasty EPR (n = 36) and APC (n = 17), and reverse EPR (n = 20) and APC (n = 10). RESULTS: Reverse reconstructions had improved forward elevation (85° vs. 44°, p < .001) and external rotation (30° vs. 21°; p < .001) versus a hemiarthroplasty. Reverse reconstructions had improved American Shoulder and Elbow Surgeons scores (65 vs. 57; p = .01) and Musculoskeletal Tumor Society 93 scores (72 vs. 63; p < .001) versus hemiarthroplasty. Subluxation of the reconstruction was a common (n = 23, 27%), only occurring in hemiarthroplasty patients (EPR [n = 13, 36%] and APC [n = 10, 59%]). CONCLUSION: The current series highlights the improved functional outcome in patients undergoing reconstruction with a reverse arthroplasty compared to the traditional hemiarthroplasty. Currently reverse shoulder arthroplasty (APC or EPR) is our preferred methods of reconstruction in this patient population.

The Lawrence D. Dorr Surgical Techniques & Technologies Award: Using Big Heads and Small Acetabular Components With Highly Cross-Linked Polyethylene in Total Hip Arthroplasty: Is It Safe?

BACKGROUND: Contemporary total hip arthroplasty (THA) employs larger femoral heads to optimize hip stability. However, the combination of large femoral heads and comparatively small acetabular components poses a potential risk for implant failure secondary to polyethylene (PE) liner fracture or dissociation. The purpose of this study was to evaluate the incidence of liner fracture or dissociation, implant survivorship, and PE wear rates in primary THAs using large femoral heads and small acetabular components. METHODS: Between 2000 and 2017, we retrospectively identified 882 primary THAs with 36 mm femoral heads and acetabular components ≤52 mm with highly cross-linked polyethylene liners. Mean age was 66 years, 88% were females, and mean body mass index was 30 kg/m2. We evaluated the cumulative incidences of dislocation, any revision, and any reoperation utilizing a competing risk model. Osteolysis and femoral head penetration were assessed with a validated radiographic technique at minimum 10-year follow-up (n = 18). Mean follow-up was 4 years. RESULTS: There were no liner fractures or dissociations in the entire cohort. The 10-year cumulative incidences of dislocation, any revision, and any reoperation were 3.2%, 5.6%, and 9.3%, respectively. Mean linear femoral head penetration was 0.042 mm/y and mean volumetric wear rate was 44 mm3/y. No THAs demonstrated evidence of osteolysis or component loosening at long-term follow-up. CONCLUSION: In a large cohort of primary THAs pairing large femoral heads with small acetabular components, there was no evidence of liner fracture or dissociation. Cumulative incidences of dislocation, any revision, and any reoperation were low at mid-term. LEVEL OF EVIDENCE: IV.

Primary Total Hip Arthroplasty in Patients With Ankylosing Spondylitis.

BACKGROUND: Ankylosing spondylitis (AS) is a common inflammatory spondyloarthropathy with hip involvement in 40% of patients. With the renewed interest in the hip-spine interplay, this study aimed to define long-term outcomes of primary total hip arthroplasty (THA) in the setting of AS. METHODS: We identified 309 hips (219 patients) with AS treated with primary THA from 1969 to 2018. Mean age was 49 years, 80% were males, and mean body mass index was 28 kg/m2. Cumulative incidences of any revision, reoperation, and dislocation were calculated utilizing a competing risk analysis. Harris Hip Scores and complications were also reported. Mean follow-up was 16 years. RESULTS: The cumulative incidence of any revision after primary THA was 2.3% at 5 years and 17.5% at 20 years. The most common reasons for revision (n = 73) were aseptic loosening (41%), osteolysis/polyethylene (PE) wear (30%, all with conventional PE), and femoral component fracture (8%). The cumulative incidence of dislocation was 1.9% at 5 years and 2.9% at 20 years. Younger age was associated with increased risk of revision (hazard ratio (HR) = 1.3, P < .01) and reoperation (HR = 1.2, P < .01), but not dislocation (HR = 0.7, P = .1). Twenty-eight hips (9%) experienced a postoperative complication not requiring reoperation. The mean Harris Hip Score improved from 51 to 76 after THA (P < .001). CONCLUSION: In this series of 309 primary THAs in patients with AS, the 20-year cumulative incidence of any revision after primary THA was 17.5%. Aseptic loosening, osteolysis/PE wear, and femoral component fracture were the most common reasons for revision. Notably, the cumulative incidence of dislocation at 20 years was only 2.9%. LEVEL OF EVIDENCE: Level IV.

Revision Total Hip Arthroplasty in Patients With Ankylosing Spondylitis: Long-Term Results.

BACKGROUND: Ankylosing spondylitis (AS) is a common inflammatory spondyloarthropathy with hip involvement in 40% of patients. With the recent interest in the hip-spine interplay, the purpose of this study was to define the long-term outcomes of revision total hip arthroplasty (THA) in the setting of AS. METHODS: 174 hips in patients with AS treated with revision THA from 1969 to 2016 were identified. Mean age at revision THA was 53 years and 76% were male. Cumulative incidences of any re-revision, reoperation, and dislocation were calculated using a competing risk analysis. Mean follow-up was 13 years. RESULTS: The cumulative incidence of any re-revision after index revision THA was 7% at 5 years and 36% at 20 years. Cumulative incidence of any reoperation was 9% at 5 years and 38% at 20 years. Cumulative incidence of dislocation was 6% at 5 years and 8% at 20 years. Revision THAs performed with contemporary implants (2000-2016) had a lower but statistically nonsignificant cumulative incidence of any re-revision when compared with historical implants (before 2000) at 5 years (5% vs 8%), 10 years (11% vs 18%), and 15 years (11% vs 38%) (hazard ratio, 0.47; 95% confidence interval, 0.17-1.33; P = .016). CONCLUSION: In this large series of 174 revision THAs in patients with AS, the cumulative incidence of dislocation was 8% at 20 years. The 20-year cumulative incidence of any re-revision was 36%, which is similar to reported rates in patients with comparable demographic features without AS. LEVEL OF EVIDENCE: Level IV.

High incidence of complications associated with shoulder girdle reconstruction utilizing a Stryker proximal humerus cap endoprosthesis following Tikhoff-Linberg resections.

INTRODUCTION: The Tikhoff-Linberg procedure is a limb salvage technique for tumours of the shoulder girdle which preserves function of the hand and elbow; however, shoulder function is limited. A humeral cap endoprosthesis (Stryker Orthopedics, Mahwah, NJ, USA) was developed within the Modular Replacement System (MRS) to act as a functional spacer for these defects; however, the outcomes of this implant have not been described. METHODS: Thirty-three (17 male, 16 female) patients underwent a Tikhoff-Linberg procedure at our institution. Of these, 17 (11 females, 6 males) were reconstructed with a MRS humerus endoprosthesis. Outcomes and complications were compared between patients who were reconstructed (n = 17) and those who were not (n = 16). RESULTS: Complications occurred in 14 (42%) patients, with more complications in patients who were reconstructed (n = 11, 65% vs. n = 3, 19%, p = 0.01). Endoprosthetic complications included stress shielding of the bone/prosthesis interface (n = 7, 41%) and subluxation/instability (n = 5, 29%), leading to a revision surgery in two (12%). Post-operatively, the mean Musculoskeletal Tumor Society Score (MSTS93) was 67 ± 11%, with no difference in the mean MSTS93 between patients who were reconstructed and those who were not (67 ± 10% vs. 68 ± 12%, p = 0.77). CONCLUSIONS: Reconstruction with a MRS humerus cap endoprosthesis resulted in a high rate of complications following a Tikhoff-Linberg procedure. Stress shielding and subluxation were common, and as such, the use of this prosthesis is limited to cases where a standard implant is not a feasible option.

Rotating-Hinge Revision Total Knee Arthroplasty for Treatment of Severe Arthrofibrosis.

BACKGROUND: Revision total knee arthroplasty (TKA) for arthrofibrosis is fraught with challenges. Because rotating-hinge (RH) prostheses do not rely on ligaments for stability, a more aggressive soft-tissue release is possible. The goal of this study was to report arc of motion, Knee Society scores, and implant survivorship in patients with arthrofibrosis revised with an RH. METHODS: Thirty-four patients revised with an RH for arthrofibrosis were matched to 68 patients revised without an RH. The mean age was 63 years, 62% were female, mean body mass index was 31 kg/m2, and mean follow-up was 6 years (range, 2-15 years). RESULTS: The mean arc of motion increased 20° (74°-94°) in the RH group versus 12° (87°-99°) in the non-RH group (P = .048). Two manipulations under anesthesia were performed in the RH group compared to 9 in the non-RH group (P = .2). Knee Society scores increased significantly in both groups (P = .01 and P < .001, respectively). Survivorship free of revision for aseptic loosening at 10 years was 83% in the RH group versus 96% in the non-RH group (P = .44). Survivorship free of any revision at 10 years was 54% in the RH group and 90% in the non-RH group (P = .03). Forty percent of the revisions in the RH group were related to insert and bushing exchanges. CONCLUSION: In this series, patients with arthrofibrosis revised to an RH TKA had a 20° improvement in arc of motion and manipulations under anesthesia were half as common. However, there was a higher risk of re-revision in the RH group. LEVEL OF EVIDENCE: III.

Robotic-Assisted Total Hip Arthroplasty: Outcomes at Minimum Two-Year Follow-Up.

BACKGROUND: Component malposition in total hip arthroplasty (THA) contributes to instability and early failure. Robotic-assisted total hip arthroplasty (rTHA) utilizes CT-based planning with haptically-guided bone preparation and implant insertion to optimize component position accuracy. This study compared acetabular component position and postoperative complications following manual THA (mTHA) with rTHA. MATERIALS AND METHODS: Consecutive primary THAs performed by one surgeon at three intervals were analyzed in this retrospective cohort study: the initial 100 consecutive manual THAs (mTHA) in clinical practice (year 2000), the last consecutive 100 mTHA before rTHA introduction (year 2011), and the first consecutive 100 rTHA (year 2012). Acetabular abduction (AAB) and anteversion (AAV) angles were measured using validated software. The Lewinnek safe zone was used to define accuracy (AAB 40°±10° and AAV 15°±10°). Comparisons included operative time, estimated blood loss (EBL), infection rate, and dislocation rate. RESULTS: The rate of acetabular component placement within Lewinnek safe zone was the highest in the rTHA cohort (77%), followed by late mTHA (45%) and early mTHA (30%) (p<0.001). Robotic-assisted THA resulted in an additional 71% improvement in accuracy in the first year of use (p<0.001). Dislocation rate was 5% with early mTHA, 3% in the late mTHA cohort, and 0% in the rTHA cohort within the first two years postoperatively. There were no statistically significant differences in the rate of infection between groups. CONCLUSION: Robotic-assisted THA improved acetabular component accuracy and reduced dislocation rates when compared with mTHA. Further study is needed to determine if similar improvements will be noted in larger multicenter studies using alternative surgical approaches.

Improved Functional Outcomes with Robotic Compared with Manual Total Hip Arthroplasty.

INTRODUCTION: Functional outcome following total hip arthroplasty (THA) is affected by accurate component positioning and restoration of hip biomechanics. Robotic-assisted THA (rTHA) has been shown to improve accuracy of component positioning, but its impact on functional outcomes has not been demonstrated. The purpose of this study was to compare: 1) operative time; 2) estimated blood loss; 3) postoperative complications; and 4) patient-reported outcome measures (PROMs) between patients who either underwent rTHA or manual THA (mTHA). MATERIALS AND METHODS: In this retrospective cohort study, a single-center database was used to identify all patients who underwent primary THA since introduction of rTHA at a large academic medical center. Surgical factors including operative time and estimated blood loss as well as postoperative complications were recorded. Validated PROMs following rTHA (n = 100) were compared with consecutive mTHA cases (n = 100) performed by the same fellowship-trained surgeon at a minimum one-year follow-up (24 ± 6 months). PROMs included the Short-Form 12 Health Survey (SF-12), UCLA activity score (UCLA), Western Ontario and McMaster (WOMAC) Osteoarthritis Index, and modified Harris Hip Score (mHHS). A categorical analysis was performed to determine differences in proportions of patients with mHHS scores of 90 to 100, 80 to 89, 70 to 79, and < 70 points between the two groups. Chi-square and two-tailed t-tests were used to compare categorical and continuous data between cohorts. RESULTS: Mean operative time was nine minutes longer for the rTHA group compared with the mTHA group (131 ± 23 min vs. 122 ± 29 min, respectively, p = 0.012). Estimated intraoperative blood loss was significantly reduced for the rTHA group when compared to the mTHA group (374 ± 133 mL vs. 423 ± 186 mL, p = 0.035), and there was no difference in overall complication rates between the two groups (p = 0.101). Robotic-assisted THA demonstrated significantly higher mean postoperative mHHS (92.1 ± 10.5 vs. 86.1 ± 16.2, p = 0.002) and mean UCLA scores (6.3 ± 1.8 vs. 5.8 ± 1.7, p = 0.033) compared with mTHA. The difference between pre- and postoperative mHHS scores was statistically significant when comparing rTHA with mTHA (43.0 ± 18.8 vs. 37.4 ± 18.3, p = 0.035). There were no significant differences in SF-12 or WOMAC scores. There was a significantly higher proportion of patients with mHHS scores between 90 to 100 points (75% vs. 61%, p = 0.034) and a lower percentage with scores < 70 points (6% vs. 19%, p = 0.005) in the rTHA cohort compared with the mTHA cohort. DISCUSSION: The rTHA cohort demonstrated significantly higher mean postoperative UCLA scores, higher mean postoperative mHHS scores, and a greater percentage of patients with mHHS of 90 to 100 points compared with mTHA at a minimum one-year follow-up. To our knowledge, this is the first study to demonstrate that robotic-assisted THA leads to improved patient-reported outcomes. The observed improvement in functional outcomes following rTHA is encouraging and warrants additional multi-center studies to determine if these advantages are maintained at longer follow-up intervals.