Good stability and mid-term subjective outcomes after repeated anterior cruciate ligament (ACL) revision surgery using allografts.

PURPOSE: To evaluate the mid-term clinical outcomes of a cohort of patients who underwent multiple ACL revision reconstructions. The hypothesis was that patients with pre-existing meniscal deficiency conditions, malalignment and cartilage degeneration would have obtained lower results. METHODS: All cases of multiple ACL revisions performed with allograft tissue at one single sport-medicine institution were extracted and patients with a minimum 2 years of follow-up were included. WOMAC, Lhysolm, IKDC, and Tegner activity level before the injury and at last follow-up was collected and laxity evaluated with KT-1000 arthrometer and KiRA triaxial accelerometer. RESULTS: From a cohort of 241 ACL revisions, 28 patients (12%) with Repeated ACL Revision reconstructions were included. Fourteen cases (50%) were considered "Complex" due to the addition of meniscal allograft transplantation (8) or meniscal scaffold (3) or high tibial osteotomy (3). The remaining 14 cases (50%) were considered as "Isolate". The mean WOMAC score was 84.6 ± 11.4, Lysholm 81.7 ± 12.3, subjective IKDC 77.2 ± 12.1, and median Tegner score 6 (IQR 5-6) at pre-injury and at final follow-up. Statistically significant inferior values of WOMAC (p = 0.008), Lysholm (p = 0.02) and Subjective IKDC (p = 0.0193) were detected between "Complex" and "Isolate" revision groups. Higher average values of anterior translation at KT-1000 at both 125 N (p = 0.03) and manual maximum displacement test (p = 0.03) were reported in "Complex" with respect to "Isolate" revisions. Four patients were considered as failures and occurred in patients with "Complex" revisions, none occurred in the "Isolate" (30% vs 0%; p = 0.04). CONCLUSION: Good mid-term clinical results can be obtained after repeated ACL revision with allograft in patients who experienced multiple failures; however, those who need additional procedure due to malalignment or post-meniscectomy syndrome reported lower objective and subjective results. LEVEL OF EVIDENCE: III.

The 90-day Readmission Rate after Single-Bundle ACL Reconstruction Plus LET: Analysis of 2,559 Consecutive Cases from a Single Institution.

The aim of the present study is to examine the readmission rate within 90 days of a cohort of patients, who underwent an arthroscopic anterior cruciate ligament (ACL) reconstruction with a lateral extraarticular tenodesis, from a single highly specialized sports traumatology department. From our institutional database, we identified 2,559 patients (78.5% males and 21.5% females, with a mean age at surgery of 30.9 ± 11.5 years) who underwent primary ACL reconstruction with the same "over-the-top" technique plus lateral extraarticular tenodesis (LET) from January 2010 to December 2017. From this count, we extracted all patients who were readmitted within 90 days and focused on causes of readmission and reoperation rate. Moreover, a multivariate logistic regression was performed to identify possible variables, such as gender, age, and concomitant meniscus surgery, which could predict the risk of early readmission. From the aforementioned cohort, 58 patients (2.27%) were readmitted within 90 days from surgery after a mean time of 31 ± 23 days. The most common cause of readmission was fever and knee swelling (0.78%), followed by superficial infection (0.63%), deep infection (0.55%), and joint stiffness (0.23%). The patients' age and meniscal lesions requiring concomitant arthroscopic treatment were found to be correlated to an increased risk of early readmission. Superficial infections were more common in female patients (odds ratio [OR] = 3.01), whereas the meniscal treatment was also a significant risk factor specifically for deep infections (OR = 3.56). In conclusion, this technique of arthroscopic ACL reconstruction with LET showed a low readmission rate within 90 days from surgery. However, patients and physicians should be aware of the risk of serious complications, such as deep and superficial infections, mostly in female patients and in cases of concurrent meniscal treatments. This is a Level IV, retrospective case series study.

White Blood Cell Count Is the Most Reliable Test for the Diagnosis of Septic Arthritis After Anterior Cruciate Ligament Reconstruction: An Observational Study of 38 Patients.

PURPOSE: (1) To evaluate the diagnostic testing performance of the synovial white blood cell (WBC) count, polymorphonuclear cell percentage, and synovial glucose, synovial protein, synovial lactate dehydrogenase, and synovial C-reactive protein levels as diagnostic markers for the diagnosis of septic arthritis after anterior cruciate ligament (ACL) reconstruction; (2) to define the ideal thresholds of the aforementioned tests, leading to the optimal sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy; and (3) to define the sensitivity of synovial fluid culture and synovial tissue sample culture, as well as determine whether previous antibiotic treatment may affect the accuracy of these tests. METHODS: We performed a retrospective analysis of all patients readmitted from January 2009 to September 2019 with signs suggestive of septic arthritis and undergoing a knee aspiration for synovial fluid analysis and culture. The receiver operating characteristic curve and the associated area under the curve were constructed for the aforementioned synovial markers. Sensitivity, specificity, PPV, NPV, and accuracy were calculated for the obtained optimal values. Sensitivity was also calculated for synovial fluid culture and synovial tissue sample culture, and the influence of previous antibiotic treatments on culture sensitivity was evaluated. RESULTS: Among 3,408 cases of ACL reconstruction, after the exclusion of 13 patients not meeting the inclusion criteria, 24 infected and 14 uninfected patients were reviewed and included in the analysis. The diagnosis was confirmed by the presence of 2 positive culture findings with the same isolated microorganism or at least 3 of the 4 following criteria: elevated serum C-reactive protein level and erythrocyte sedimentation rate, positive results of histologic analysis of synovial tissue, macroscopic evidence of purulence, and 1 positive culture finding. The receiver operating characteristic curve analysis showed that the most reliable marker for the diagnosis of septic arthritis after ACL reconstruction was the synovial WBC count (area under the curve, 0.89). A cutoff value of 28,100 cells/mL presented the highest accuracy (0.85), highest PPV (0.94), and highest NPV (0.76); moreover, with the threshold set at 40,000 cells/mL, postoperative infection could be diagnosed with 100% specificity. The sensitivity of synovial fluid culture was significantly lower than the sensitivity of synovial tissue sample culture (0.63 vs 0.96, P = .0045); moreover, the sensitivity further decreased if patients took antibiotics before aspiration (0.44 vs 0.73), although this decrease was not statistically significant. CONCLUSIONS: The synovial WBC count is the most reliable test for the diagnosis of septic arthritis after ACL reconstruction. Although the sensitivity of synovial fluid culture is affected by previous antibiotic treatment, the synovial WBC count is not influenced and proves to be useful in the diagnosis of this uncommon complication. LEVEL OF EVIDENCE: Level II, diagnostic study.

Graft-Preserving Arthroscopic Debridement With Hardware Removal Is Effective for Septic Arthritis After Anterior Cruciate Ligament Reconstruction: A Clinical, Arthrometric, and Magnetic Resonance Imaging Evaluation.

BACKGROUND: Arthroscopic debridement with graft preservation has been advocated as the treatment of choice for septic arthritis after anterior cruciate ligament (ACL) reconstruction, but no previous studies have investigated if hardware removal, while retaining the graft in situ, improves the success rate. Moreover, it is unclear whether the premature removal of fixation devices may affect graft integration and knee stability. PURPOSE/HYPOTHESIS: The purpose was to assess the clinical and functional outcomes of patients with septic arthritis after ACL reconstruction who underwent arthroscopic debridement, while retaining the graft in situ but removing fixation devices, and to determine if premature hardware removal affects graft integrity and function. The hypothesis was that arthroscopic debridement with hardware removal would be effective in eradicating infections while not compromising graft integration and function. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: From a cohort of 2384 cases of arthroscopic ACL reconstruction, 24 patients with postoperative septic arthritis were included for the analysis; 18 patients were available for a clinical evaluation using the International Knee Documentation Committee (IKDC) form, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lysholm score, and Tegner score at a minimum 12-month follow-up. Knee laxity was assessed clinically with standardized manual laxity tests and instrumentally using an arthrometer and a triaxial accelerometer. Additionally, 3-T magnetic resonance imaging (MRI) at final follow-up was performed, focusing on the graft signal, the cartilage status, and the occurrence of arthrofibrosis. RESULTS: Eradication of the infection was achieved in all cases, and only 1 graft removal was performed because of insufficient tension. Among the remaining 23 patients, a single arthroscopic debridement procedure with hardware removal while preserving the graft was effective in 21 cases (91%) at a mean of 30 ± 37 days from ACL reconstruction to debridement. At last follow-up, 2 patients required a further ACL revision procedure. The mean IKDC, WOMAC, Lysholm, and Tegner scores of the patients available for the clinical evaluation were 75 ± 19, 90 ± 8, 79 ± 21, and 6 ± 2, respectively. No abnormal laxity was reported on manual testing, and arthrometric and accelerometer tests also demonstrated good knee stability (mean KT-1000 arthrometer side-to-side difference was 1.6 ± 1.2 mm at manual maximum force). On MRI, a good graft signal was found in 50% of cases, while concomitant signs of arthrofibrosis were detected in 81% of patients. Severe cartilage defects (International Cartilage Repair Society grade ≥3) were reported in 63% of cases. CONCLUSION: Arthroscopic debridement with hardware removal was effective in the eradication of infections after ACL reconstruction with extra-articular fixation while preserving graft integrity without compromising knee stability. Patients and surgeons should be aware of complications that might affect the outcome, particularly arthrofibrosis and chondrolysis.

Bearing thickness of unicompartmental knee arthroplasty is a reliable predictor of tibial bone loss during revision to total knee arthroplasty.

BACKGROUND: Bone defects during revision procedures for failed UKA represent a challenge even for the most experienced surgeons; therefore, an accurate preoperative planning remains essential to prevent dramatic scenarios in the surgical theatre. HYPOTHESIS: Our hypothesis is that bearing thickness used in original UKA represents a reliable predictor of severe tibial bone loss, requiring a metallic augment or constrained implant, during revision to TKA. PATIENTS AND METHODS: Forty-two patients who underwent a total knee arthroplasty from failed UKA were identified from our institutional database and evaluated clinically using the Knee Society Score (KSS). A multivariate logistic regression analysis was performed using the presence of tibial augments or the need of varus-valgus constrained (VVC) prosthesis as depend variables, and patients' gender, age at revision procedure, side (medial or lateral), UKA tibial tray (all-polyethylene or metal back), bearing thickness (composite thicknesses of the metal-backed tray and insert or all-polyethylene tibial component ≤8mm or more than 8mm) and cause of failed UKA as independent variables. RESULTS: A posterior-stabilized prosthesis was used in 27 cases (64.3%). An augment was necessary in 12 patients (28.6%). Initial bearing thickness greater than 8mm was associated with greater likelihood of a VVC implant (OR=11.78, 95% CI, 1.6583 to 83.6484, p=0.0137) and a tibial augment (OR=9.59, 95% CI, 1.327 to 69.395, p=0.0251). Tibial tray design, patients' gender or age during revision surgery, side or cause of failure were not associated to increased risk of augmentation or constrained implants. DISCUSSION: Surgeons should be aware of the particular challenges that the conversion of a UKA to a TKA presents and be prepared to address them intraoperatively, with particular care to proper bone loss manage. Satisfying results can be achieved at mid-to-long term follow-up, if these procedures are planned accurately, and a precise analysis of failed UKA components, in particular bearing thickness, represents a helpful support in this context. LEVEL OF EVIDENCE: IV, retrospective case series.

Difficult primary total knee arthroplasty requiring a varus-valgus constrained implant is at higher risk of periprosthetic infection.

PURPOSE: The goal of this study was to compare the risk of periprosthetic infection of a consecutive cohort of primary varus-valgus constrained (VVC) total knee arthroplasties (TKAs), with a matched 1:1 cohort of primary posterior-stabilized (PS) TKAs. METHODS: 74 primary VVC TKAs performed in 66 patients were identified and matched 1:1 with a cohort of 74 primary PS TKAs performed in 73 patients. At last follow up, patients were clinically evaluated using the Knee Society Score (KSS). Kaplan-Meier survival curves were generated to analyze survivorship using as endpoints revision for any reason, revision for periprosthetic infection and revision for mechanical failure after excluding periprosthetic infection. A multivariate logistic regression analysis was constructed to determine whether revision surgery for periprosthetic infection was influenced by patients' gender, age, surgical time and reasons for TKA (primary vs secondary osteoarthritis). RESULTS: Demographic data were not significantly different between the two groups as regard patients' age, gender, body mass index, Charlson Comorbidity Index, reasons for replacement, and length of follow-up. Surgical time was greater in the VVC group (95.7 ± 22.5 min vs 88.6 ± 17.1 min, respectively, p = 0.032). Postoperative KSS, range of motion and radiographic data did not differ significantly between the two groups. Overall revision rate and revision rate for mechanical failure after 5 years of follow-up was not statistically different between the two groups. Considering only the revision rate due to periprosthetic infection, the risk was higher in patients with primary VVC implants (p = 0.013). The surgical time was the only factor that significantly affected the risk of revision for periprosthetic infection (OR 1.0636, CI 95% 1.0209-1.1081, p = 0.0032), whereas patients' gender, age and reason for TKA had no influence. CONCLUSIONS: Patients and surgeons should be aware of the higher risk of periprosthetic knee infection using a VVC prosthesis. However, the present study supports the use of VVC implants in cases of difficult knee replacements, since comparable clinical outcomes and overall revision rate was found after at least 5 years of follow up. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.

Metal-Backed Tibial Components Do Not Reduce Risk of Early Aseptic Loosening in Unicompartmental Knee Arthroplasty: A Systematic Review and Meta-Analysis.

Long-term results of unicompartmental knee arthroplasty (UKA) have shown a slightly higher revision rate than total knee arthroplasty (TKA), and implant fixation geometry seems to affect prosthetic survivorship. Whether metal-backed tibial component leads to superior performance over the all-polyethylene design is unclear, and a lack of evidence exists in literature. Our purpose was to demonstrate which implant design of UKA (all-polyethylene or metal-backed tibial component) is clinically superior regarding revision rates and clinical functioning, and investigate the role of potential factors that could affect the revision rate. A systematic review was conducted for clinical studies comparing all-polyethylene and metal-backed tibial components used in primary UKAs in terms of revision rates and clinical scores. Meta-regression techniques were used to explore factors modifying the observed effect. All causes of revision were extracted and analyzed, to find statistically significant differences between the two groups. Our research strategy generated a systematic review of nine studies comprising 1,101 UKAs in 1,088 patients with 87 revisions for any reason. Meta-analysis showed a higher, but not statistically significant, risk of aseptic revision in the all-polyethylene group. Studies with a smaller sample size and higher percentage of female patients were correlated to a higher relative risk of revision in favor of all-polyethylene UKAs. Differently, patients' age and duration of follow-up did not influence the risk ratio. The main cause for revision was aseptic loosening in both implants' component, with no statistically differences in the two groups examined. Our results do not show a superiority of the metal-backed tibial component in UKAs in terms of survivorship, although extreme care must be given for patients with high risk of early failure, such as female patients. However, surgical experience, in combination with careful patient selection, remains paramount and may lead to better long-term outcomes in patients requiring UKA. This is a Level III, therapeutic study.

Return to Sports after Unicompartmental Knee Arthroplasty: Reality or Utopia? A 48-Month Follow-Up Prospective Study.

Unicompartmental knee arthroplasty (UKA) has increased in popularity in the last years, also in younger and more active patients with great expectancies. The purpose of our study was to investigate the change in sports activities before and after medial UKA. We surveyed 53 athletic patients; all underwent cemented medial UKA, to determine not only their subjective and objective evaluation of clinical status with Hospital for Special Surgery (HSS) and visual analog score (VAS) score, but also their sporting and recreational activities at a mean follow-up of 48 ± 6 months (range, 18-56 months). At the last follow-up, 48 of 53 patients were engaged in sports and recreational disciplines, resulting in a return to activity rate of 90%. No early failure and no cases of revision were reported. The frequency of activities (sessions per week) and the time session remained constant at the time of survey. The most common activities after surgery were hiking, cycling, and swimming. Several high-impact activities, as well as skiing and football, had a significant decrease in participating patients. There were no gender-, age- and body mass index (BMI)-related differences. UKA can be considered a viable alternative in relatively young patients with high functional requirements and the correct indications, however, warning the patients about the risks of polyethylene wear and early loosening of the prosthetic components as a result of the resumption of sporting activities in high impact. LEVEL OF EVIDENCE: Prospective case series, level 4.

Pedicled omental flaps in the treatment of complex spinal wounds after en bloc resection of spine tumors.

STUDY DESIGN: The present paper presents a retrospective study of 5 patients who underwent pedicled omental flap procedure following spine tumor removal. SUMMARY OF BACKGROUND DATA: Postoperative wound dehiscence represents a major complication in spinal surgery, particularly after en bloc tumor resection, because of the extended sacrifice of soft tissues and adjuvant radiation therapy and chemotherapy. METHODS: Five patients, with a mean age of 52 years (range, 24-71 years), who underwent omental flaps for the treatment of postoperative complication in spine tumor resections were retrospectively evaluated. RESULTS: Four of 5 patients underwent omental transposition after a mean of 15 months (range, 4-27) from the previous surgery because of dehiscence of the wound (all of them had cerebrospinal fluid leak: 1 transpleural and in 3 cases, associated with deep infection), whereas one patient underwent the omental flap procedure at the time of elective spinal surgery because of several contemporary risk factors for wound healing. At the time of discharge after a mean of 36 days (range, 23-53), all patients had well-healed surgical wounds with an acceptable structural and aesthetic result. One of the patients had ileus, requiring surgical lysis of abdominal adhesions 3 months after omentum flap procedure. No other complications were observed. CONCLUSION: Our data suggest that pedicled omental flap is a viable option for the treatment of complicated spinal wounds, helping in the resolution of the infection and CSF leak.